PURPOSE: To obtain superior characteristics in sensitivity and potential stability at the time of repeated uses by using an azo pigment specified in structure for a photosensitive layer.

CONSTITUTION: The azo pigment to be used is represented by formula I in which at least one of couplers (Cp)s is represesnted by formula II; Aris an optionally substituted aromatic or heterocyclic group optionally linked through a bonding group: Cp is a coupler group with a phenolic OH group; i is an integer of 1-4; each of R1-R4 is H, alkoxy, disubstituted amino group or the like, independent of each other; each of Z1 and Z2 is 0 or S, independent of each other; each of j and k is an integer or 1-5; each of l and m is 0 or 1, thus permitting practicable high sensitivity characteristics and stable potential characteristics at the time of repeated use to be obtained.