To provide a photocurable sealant composition, a sealing layer using the photocurable sealant composition, especially a technique for sealing a housing for electronic parts including hard disk dive, electronic elements and electronic parts.

The invention relates to the photocurable sealant composition comprising (A) one or a plurality of two functional (meth)acrylates selected from a group of compounds having (meth)acryloyl groups on both ends of an aliphatic chain hydrocarbon comprising a main 3-15C chain and optionally having a branch chain, (B) one or a plurality of mono functional (meth)acrylates selected from a group of compounds having (meth)acryloyl group on one end of a 6-20C aliphatic alkyl skeleton with, optionally having a branch, (C) a styrene-isobutylene-styrene block copolymer, (D) a photopolymerization initiator and (E) a silica powder, and the invention relates to the component with a sealing layer formed by coating the composition on a component and irradiating it with a light.