A novel organic amine salt or salt with quaternary ammonium ion of 3-{[((2E)-2-{1-[5-(4-t-butylphenyl)-4-hydroxy-3-thienyl]ethylidene}hydrazino)carbonothioyl]amino}benzoic acid having useful properties as a drug is provided. A novel organic amine or salt with quaternary ammonium ion of 3-{[((2E)-2-{1-[5-(4-t-butylphenyl)-4-hydroxy-3-thienyl]ethylidene}hydrazino)carbonothioyl]amino}benzoic acid, a method for producing the organic amine salt or the salt with quaternary ammonium ion and a platelet increasing agent.
