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

    <schemaVersion>X0202</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2007-01-30</periodOfReport>

    <noSecuritiesOwned>1</noSecuritiesOwned>

    <issuer>
        <issuerCik>0000906193</issuerCik>
        <issuerName>KEY TECHNOLOGY INC</issuerName>
        <issuerTradingSymbol>KTEC</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001388835</rptOwnerCik>
            <rptOwnerName>Brausen James R</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O KEY TECHNOLOGY INC</rptOwnerStreet1>
            <rptOwnerStreet2>150 AVERY STREET</rptOwnerStreet2>
            <rptOwnerCity>WALLA WALLA</rptOwnerCity>
            <rptOwnerState>WA</rptOwnerState>
            <rptOwnerZipCode>99362</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>1</isOther>
            <officerTitle></officerTitle>
            <otherText>Corporate Controller</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <remarks>No securities are beneficially owned.</remarks>

    <ownerSignature>
        <signatureName>James R. Brausen</signatureName>
        <signatureDate>2007-02-05</signatureDate>
    </ownerSignature>
</ownershipDocument>
