To obtain a pyridinethiol compound having a broad antibacterial spectrum and strong antibacterial power, exhibiting high microbicidal property, mildewproofing property and antiseptic property against a wide variety of microorganisms such as yeasts, wood decay bacteria, mold and bacteria, and to obtain an industrial antibacterial composition containing the compound.

The antiseptic, mildewproofing, bactericidal, bacteriostatic and algicidal agent contains an amine salt of a pyridinethiol expressed by formula (1) (R is methyl, ethyl, 2-hydroxyethyl, tetrahydrofurfuryl, 3-methyl-2-pyridyl or 3-mercapto-2,4,5-thiadiazolyl).