The present invention is a bactericide composition containing: (a) an alkyl or an alkenyl amine oxide having an alkyl group or an alkenyl group with 7 or more and 18 or less carbons； and (b) a mono- or polyoxyalkylene alkyl or alkenyl amine having an alkyl group or an alkenyl group with 8 or more and 24 or less carbons and having an average number of added moles of the oxyethylene group of one or more and 8 or less.
