The present invention provides a bactericide containing a 2-aminonicotinic acid ester derivative as an active ingredient.The active ingredient is represented by the following formula [I] :(wherein, R1 represents a hydrogen atom or a C1-C4 alkyl group, R2 represents a hydrogen atom or a C1-C4 alkyl group, R1 and R2 may be combined together to form an alkylene chain, R3 represents a hydrogen atom or a C1-C4 alkyl group, R4 represents a hydrogen atom, a cyano group or a C1-C4 alkyl group, R5 and R6 independently represent a hydrogen atom, a halogen atom, a C1-C4 alkyl group, a C1-C4 alkoxy group, a C1-C4 alkylthio group, a C1-C4 alkylsulfinyl group, a C1-C4 alkylsulfonyl group, a nitro group, a cyano group, a C1-C4 haloalkyl group, a C1-C4 haloalkoxy group or a C1-C4 haloalkylthio group, A and B independently represent a methine (CH) group or a nitrogen atom).
