It is an object of the present invention to provide: a curable composition that has photocurability and provides a cured product excellent in insulating properties; and the cured product. This can be achieved by a photocurable composition that contains, as essential components, (A) a modified polyorganosiloxane compound having a photopolymerizable functional group and an SiH group, (B) a compound having a carbon-carbon double bond, and (C) a photopolymerization initiator. A thin film produced from the curable composition of the present invention has excellent insulating properties. Since the curable composition of the present invention can form a film by solution coating, it is applicable to provide thin-film insulating materials that can be formed by solution coating.