<；P>；PROBLEM TO BE SOLVED: To provide a cysteine derivative having good safety without malodor problems, and to provide a cosmetic comprising the cysteine derivative. <；P>；SOLUTION: The cysteine derivative (except thiazoline-2,4-dicarboxylic acid and 2-methylthiazoline-2,4-dicarboxylic acid) is represented by general formula (I) [wherein, X represents OR1 or NHR2 (wherein, R1 represents a hydrogen atom or a 1-22C alkyl group； and R2 represents a hydrogen atom or a 1-22C alkyl group)； Y represents OR3 or NHR4 (wherein, R3 represents a hydrogen atom or a 1-22C alkyl group which may be substituted； and R4 represents a hydrogen atom or a 1-22C alkyl group)； and Z represents a hydrogen atom or a 1-22C alkyl group] or a salt thereof. <；P>；COPYRIGHT: (C)2010,JPO&INPIT
