<?xml version="1.0" encoding="us-ascii"?><InstanceReport xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"><Version>2.4.0.8</Version><ReportLongName>111 - Disclosure - Investment</ReportLongName><DisplayLabelColumn>true</DisplayLabelColumn><ShowElementNames>false</ShowElementNames><RoundingOption /><HasEmbeddedReports>false</HasEmbeddedReports><Columns><Column FlagID="0"><Id>1</Id><IsAbstractGroupTitle>false</IsAbstractGroupTitle><LabelSeparator>

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</LabelSeparator><Level>1</Level><ElementName>us-gaap_InvestmentsAbstract</ElementName><ElementPrefix>us-gaap_</ElementPrefix><IsBaseElement>true</IsBaseElement><BalanceType>na</BalanceType><PeriodType>duration</PeriodType><IsReportTitle>false</IsReportTitle><IsSegmentTitle>false</IsSegmentTitle><IsCalendarTitle>false</IsCalendarTitle><IsEquityPrevioslyReportedAsRow>false</IsEquityPrevioslyReportedAsRow><IsEquityAdjustmentRow>false</IsEquityAdjustmentRow><IsBeginningBalance>false</IsBeginningBalance><IsEndingBalance>false</IsEndingBalance><IsReverseSign>false</IsReverseSign><FootnoteIndexer /><Cells><Cell FlagID="0" ContextID="" UnitID=""><Id>1</Id><IsNumeric>false</IsNumeric><IsRatio>false</IsRatio><DisplayZeroAsNone>false</DisplayZeroAsNone><NumericAmount>0</NumericAmount><RoundedNumericAmount>0</RoundedNumericAmount><NonNumbericText /><FootnoteIndexer /><CurrencyCode /><CurrencySymbol /><IsIndependantCurrency>false</IsIndependantCurrency><ShowCurrencySymbol>false</ShowCurrencySymbol><DisplayDateInUSFormat>false</DisplayDateInUSFormat></Cell></Cells><ElementDataType>xbrli:stringItemType</ElementDataType><SimpleDataType>string</SimpleDataType><IsTotalLabel>false</IsTotalLabel><UnitID>0</UnitID><Label>Investments [Abstract]</Label></Row><Row FlagID="0"><Id>2</Id><IsAbstractGroupTitle>false</IsAbstractGroupTitle><LabelSeparator>

</LabelSeparator><Level>2</Level><ElementName>mbmi_InvestmentsTextBlock</ElementName><ElementPrefix>mbmi_</ElementPrefix><IsBaseElement>false</IsBaseElement><BalanceType>na</BalanceType><PeriodType>duration</PeriodType><IsReportTitle>false</IsReportTitle><IsSegmentTitle>false</IsSegmentTitle><IsCalendarTitle>false</IsCalendarTitle><IsEquityPrevioslyReportedAsRow>false</IsEquityPrevioslyReportedAsRow><IsEquityAdjustmentRow>false</IsEquityAdjustmentRow><IsBeginningBalance>false</IsBeginningBalance><IsEndingBalance>false</IsEndingBalance><IsReverseSign>false</IsReverseSign><PreferredLabelRole>verboseLabel</PreferredLabelRole><FootnoteIndexer /><Cells><Cell FlagID="0" ContextID="P01_01_2013To06_30_2013" UnitID=""><Id>1</Id><IsNumeric>false</IsNumeric><IsRatio>false</IsRatio><DisplayZeroAsNone>false</DisplayZeroAsNone><NumericAmount>0</NumericAmount><RoundedNumericAmount>0</RoundedNumericAmount><NonNumbericText>              &lt;table border="0" style="clear:both;width:100%; table-layout:fixed;"&gt;  &lt;tr&gt;  &lt;td&gt;&lt;/td&gt;  &lt;/tr&gt;  &lt;/table&gt;    &lt;div style="clear:both; FONT-FAMILY:Times New Roman;FONT-SIZE: 10pt;MARGIN: 0pt 0px; FONT: 10pt Times New Roman, Times, Serif "&gt;  &lt;div style="clear:both; FONT-FAMILY:Times New Roman;FONT-SIZE: 10pt"&gt;  &lt;table style="clear:both;WIDTH: 100%; FONT: 10pt Times New Roman, Times, Serif"  cellspacing="0" cellpadding="0"&gt;  &lt;tr style="VERTICAL-ALIGN: top"&gt;  &lt;td style="TEXT-ALIGN: justify; WIDTH: 0%"&gt;  &lt;div&gt;&lt;font style="FONT: 10pt Times New Roman, Times, Serif"&gt;&lt;b&gt;  4&lt;/b&gt;&lt;/font&gt;&lt;/div&gt;  &lt;/td&gt;  &lt;td style="WIDTH: 5%"&gt;  &lt;div&gt;&lt;font style="FONT: 10pt Times New Roman, Times, Serif"&gt;&lt;b&gt;  .&lt;/b&gt;&lt;/font&gt;&lt;/div&gt;  &lt;/td&gt;  &lt;td style="TEXT-ALIGN: justify; WIDTH: 95%"&gt;  &lt;div&gt;&lt;font style="FONT: 10pt Times New Roman, Times, Serif"&gt;&lt;b&gt;&lt;u&gt;  Investment&lt;/u&gt;&lt;/b&gt;&lt;/font&gt;&lt;/div&gt;  &lt;/td&gt;  &lt;/tr&gt;  &lt;/table&gt;  &lt;/div&gt;    &lt;div style="clear:both; FONT-FAMILY:Times New Roman;FONT-SIZE: 10pt;TEXT-ALIGN: justify; TEXT-INDENT: 0.5in; MARGIN: 0pt 0px; FONT: 10pt Times New Roman, Times, Serif"&gt;  &amp;#160;&lt;/div&gt;    &lt;div style="clear:both; FONT-FAMILY:Times New Roman;FONT-SIZE: 10pt;TEXT-ALIGN: justify; MARGIN: 0pt 0px; FONT: 10pt Times New Roman, Times, Serif"&gt;  On October 29, 2012, the Company, MAB-C, and WGB Kinsey &amp;amp;  Company (&amp;#8220;Kinsey&amp;#8221;) entered into an Equity Exchange  Agreement (&amp;#8220;Equity Exchange Agreement&amp;#8221;). In accordance  with the Equity Exchange Agreement, the Company issued &lt;font style=" FONT-SIZE: 10pt"&gt;5,000,000&lt;/font&gt; shares of their common stock to  Kinsey in exchange for a &lt;font style=" FONT-SIZE: 10pt"&gt;25&lt;/font&gt;%  ownership for MAB-C in Kinsey. &lt;font style=" "&gt;Additionally, should  the value of the 5,000,000 shares of common stock fail to be valued  at $5,000,000 on December 31, 2013, the Company must issue  additional shares of common stock to achieve that value for  Kinsey.&lt;/font&gt; The common shares issued have been valued at $&lt;font  style=" FONT-SIZE: 10pt"&gt;500,000&lt;/font&gt;, as the price of MBMI  common stock was trading at $&lt;font style=" FONT-SIZE: 10pt"&gt;0.10&lt;/font&gt; per share, and no valuation has been  provided for Kinsey at this time.&lt;/div&gt;    &lt;div style="clear:both; FONT-FAMILY:Times New Roman;FONT-SIZE: 10pt;TEXT-ALIGN: justify; TEXT-INDENT: 0.5in; MARGIN: 0pt 0px; FONT: 10pt Times New Roman, Times, Serif"&gt;  &amp;#160;&lt;/div&gt;    &lt;div style="clear:both; FONT-FAMILY:Times New Roman;FONT-SIZE: 10pt;TEXT-ALIGN: justify; MARGIN: 0pt 0px; FONT: 10pt Times New Roman, Times, Serif"&gt;  Kinsey, based in Zimbabwe, Africa, has operated since 1955 in the  mining and construction industry. They own their own mining  equipment, including a fleet of articulated dump trucks, front and  wheeled loaders, excavators, dozers and graders. With both open pit  and open cast mining experience ranging from chrome to platinum to  gold, they possess all the experience necessary to efficiently  perform all the mining operations at the Dodge Mines.&lt;/div&gt;    &lt;div style="clear:both; FONT-FAMILY:Times New Roman;FONT-SIZE: 10pt;TEXT-ALIGN: justify; TEXT-INDENT: 0.5in; MARGIN: 0pt 0px; FONT: 10pt Times New Roman, Times, Serif"&gt;  &amp;#160;&lt;/div&gt;    &lt;div style="clear:both; FONT-FAMILY:Times New Roman;FONT-SIZE: 10pt;TEXT-ALIGN: justify; MARGIN: 0pt 0px; FONT: 10pt Times New Roman, Times, Serif"&gt;  The investment has been accounted for as an equity investment under  ASC 323. In accordance with the ASC, the investment will be  maintained at fair value, and increased or decreased based upon the  net income or loss of Kinsey as well as any contributions made and  dividends paid. The Company&amp;#8217;s investment decreased $&lt;font  style=" FONT-SIZE: 10pt"&gt;144,158&lt;/font&gt; as a result of the  incremental loss of Kinsey for the six months ended June 30, 2013  at &lt;font style=" FONT-SIZE: 10pt"&gt;25&lt;/font&gt;% ownership by  MAB-C.&lt;/div&gt;  &lt;/div&gt;        </NonNumbericText><FootnoteIndexer /><CurrencyCode /><CurrencySymbol /><IsIndependantCurrency>false</IsIndependantCurrency><ShowCurrencySymbol>false</ShowCurrencySymbol><DisplayDateInUSFormat>false</DisplayDateInUSFormat></Cell></Cells><ElementDataType>nonnum:textBlockItemType</ElementDataType><SimpleDataType>na</SimpleDataType><ElementDefenition>The entire disclosure for investments.</ElementDefenition><ElementReferences>No definition available.</ElementReferences><IsTotalLabel>false</IsTotalLabel><UnitID>0</UnitID><Label>Investments [Text Block]</Label></Row></Rows><Footnotes /><IsEquityReport>false</IsEquityReport><ReportName>Investment</ReportName><MonetaryRoundingLevel>UnKnown</MonetaryRoundingLevel><SharesRoundingLevel>UnKnown</SharesRoundingLevel><PerShareRoundingLevel>UnKnown</PerShareRoundingLevel><ExchangeRateRoundingLevel>UnKnown</ExchangeRateRoundingLevel><HasCustomUnits>true</HasCustomUnits><IsEmbedReport>false</IsEmbedReport><IsMultiCurrency>false</IsMultiCurrency><ReportType>Sheet</ReportType><RoleURI>http://www.Mabweminerals.com/role/Investment</RoleURI><NumberOfCols>1</NumberOfCols><NumberOfRows>2</NumberOfRows></InstanceReport>
