Curable composition and sealing method

A sealing method comprising the steps of applying a curable composition comprising (a) a vinyl-based polymer containing at least one (meth)acryloyl group in a molecule thereof and having a number average molecular weight of 500 to 1,000,000, (b) an ethylenic unsaturated group-containing compound, (c) a thixotropic property-imparting agent, (d) fumed silica surface-treated with a (meth)acryloyl group-containing silane and (e) a photopolymerization initiator to at least one side of an article to be sealed, curing the composition by light irradiation, and then, contacting another article to be sealed to the cured composition with pressure,

• wherein the component (c) is organic bentonite, or hydrophobic fumed silica whose surface is hydrophobically surface-treated with a silazane, a chlorosilane, an alkoxysilane or a polysiloxane which has only a methyl group as an organic substituent group bonding to a silicon atom.