PURPOSE: To obtain an ink composition capable of being diluted and developed with water, having excellent characteristics of its cured substance in a solder resist requiring heat resistance, chemical resistance and electrical insulating properties in the field of an electronic material field.

CONSTITUTION: This photosensitive resin composition comprises (A) a water-soluble resin obtained by simultaneously reacting 1.0 equivalent carboxyl group of a polycarboxylic acid compound containing at least two carboxyl groups in the molecule (500-500,000 molecular weight) with 0.2-1.5 equivalent of a sulfide compound containing at least one hydroxyl group and 0.8-1.2 equivalent of a monofunctional epoxy compound and/or (A') a water-soluble resin obtained by simultaneously reacting 1.0 equivalent carboxyl group of a polycarboxylic acid compound containing at least one polymerizable double bond and two or more carboxyl groups in the molecule (500-500,000 molecular weight) with 0.2-1.5 equivalent of the sulfide compound containing at least one hydroxyl group and 0.8-1.2 equivalent of the monofunctional epoxy compound and (B) a photopolymerization initiator as essential components.