To obtain a chemical agent exceedingly exhibiting germicidal and antibacterial effects against various bacteria by including a specific maleimide compound and a specific bactericide at a ratio capable of exhibiting a synergistic effect.

This industrial germicidal and antibacterial agent contains (A) a component comprising a maleimide compound (preferably maleimide) of the formula (R is H, a cycloalkyl or the like) and (B) a component selected from known germicides such as a compound having nitro group or cyano group and bromo group (preferably 2,2-dibromo-2-nitroethanol or the like), an oxime compound (preferably monochloroglyoxime or the like), an isothiazolone compound (preferably 5-chloro-2-methyl-4-isothiazolin-3-one or the like), 4,5- dichloro-1,2-dithiol-3-one, methylenebisthiocyanate and an aldehyde compound at a ratio capable of exhibiting a synergistic effect, as active components.