A photosensitive composition comprising: (A) a polymerizable compound represented by the following formula (I): A--{O--[(CH(--R.sup.1)CH(--R.sup.2)).sub.m--O].sub.n--C(.dbd.O)--C(--R.su- p.3).dbd.CH.sub.2}.sub.p (I) wherein R.sup.1, R.sup.2and R.sup.3 each represents a hydrogen atom or a methyl group, A represents a polyhydric alcohol residue or a polyhydric phenol residue, m represents an integer of from 1 to 6, n represents an integer of from 1 to 20, and p represents an integer of from 1 to 6; (B) an infrared absorber; and (C) an onium salt.