To prevent a rotation or position slippage of an insulating film which occurs in prior structures, in the conventional methods of assembling a photocoupler.

The photocoupler, according to an embodiment, includes a lead frame 6 (first lead frame), a lead frame 3 (second lead frame) having an end portion 9 bent toward the lead frame 6, a light-emitting element 1 (first optical device) fixed on the lead frame 6, a light-receiving element 2 (second optical device) fixed on the lead frame 3 so as to face the light-emitting element 1, and an insulating film 5 arranged between the light-emitting element 1 and the light-receiving element 2 and having an end portion 10 with a concave-convex shape in plane view, wherein the end portion 9 of the lead frame 3 has a concave-convex shape in plane view, and is engaged with the end portion 10 of the insulating film 5.