A compound represented by the following general formula (I): [wherein R 1 and R 2 represent an alkyl group, X represents -S-, -O- or -NH-, Y represents C or N, R 3 represents hydrogen atom or a C 1-10 alkyl group, Z represents CO-N(R 5 )- (R 5 represents hydrogen atom or a C 1-6 alkyl group) or -C(R 6 )=C(R 7 )-CO-NH-(R 6 and R 7 represent hydrogen atom or a C 1-6 alkyl group), Ar represents an aryldiyl group or a heteroaryldiyl group, and R 4 represents -COOH, -OCH 2 -COOH, -CH 2 -COOH, or -CH 2 -CH 2 -COOH], which has a retinoid action and is useful as an active ingredient of a medicament.