Examples of bis type halogen-substituted phenyl disulfide having two or more kinds of halogen atoms include bis(2-fluoro-5-chlorophenyl) disulfide, bis(2-fluoro-5-bromophenyl) disulfide, bis(2,4-difluoro-5-chlorophenyl) disulfide and bis(2,4-difluoro-5-bromophenyl) disulfide.