<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0203</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2008-10-17</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0000008328</issuerCik>
        <issuerName>ATLAS MINING CO</issuerName>
        <issuerTradingSymbol>ALMI</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001448562</rptOwnerCik>
            <rptOwnerName>TAFT DAVID A</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>ONE INTERNATIONAL PLACE</rptOwnerStreet1>
            <rptOwnerStreet2>STE 2401</rptOwnerStreet2>
            <rptOwnerCity>BOSTON</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>02110</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>13972415</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Notes 1 and 2.</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">The reporting person is a member and the president of IBS Capital LLC, which is the general partner of The IBS Turnaround Fund (QP)(A Limited Partnership) and The IBS Turnaround Fund (A Limited Partnership).  IBS Capital LLC is the investment adviser of The IBS Opportunity Fund (BVI), Ltd.</footnote>
        <footnote id="F2">The reported securities are directly owned by The IBS Turnaround Fund (QP)(A Limited Partnership), The IBS Turnaround Fund(A Limited Partnership), and The IBS Opportunity Fund (BVI), Ltd.  The reporting person disclaims beneficial ownership of the reported securities except to the extent of his pecuniary interest therein.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>David A. Taft</signatureName>
        <signatureDate>2008-10-27</signatureDate>
    </ownerSignature>
</ownershipDocument>
