To provide a compound which is useful as a material of a polymer having both photoreactivity and thermal reactivity by selecting a phenylenediamine compound having a photosensitive group.

This diamine compound is represented by formula I (wherein, X and Y are each a divalent organic group, preferably X is a single bond, CH2, COO, NH or O and Y is a single bond, COO, OOC, (CH2)mO, (CH2)mCOO, (CH2)mOOC or (CH2)m; (m) is 1-15; Z is a photosensitive group represented by one of formulas II to XI; and A is H, CH3, F, Cl Br or CH3O). The compound is reacted with an acid dianhydride in an organic polar solvent to give a polyamic acid, which is thermally or chemically imidized to give a polyimide composition containing a polyimide represented by formula XII having photosensitive groups. In the formulas, B and D are each a tetravalent organic group; E is a divalent organic group; (p) is 1-100; and (q) is 0-99. Preferably, the polyamic acid has an average mol.wt. of 5,000-1,000,000.