The present invention provides a cationically photocurable epoxy resin
composition, which contains (a) an epoxy resin component comprising an
alicyclic epoxy resin and an aromatic-ring containing epoxy resin, (b) a
cationic photoinitiator component, and (c) a filler selected from oxides,
hydroxides and carbonates containing a Group II element. This composition
exhibits improved adhesive strength to a glass such as an alkali glass,
particularly a sodium-containing glass, or a metal.