A photocoupler comprises an input side lead frame; an output side lead frame disposed facing the input side lead frame with a gap therebetween; a light emitting device mounted on a face of the input side lead frame facing the output side lead frame side; a light receiving device mounted on a face of the output side lead frame facing the input side lead frame side, opposite to and having a gap with the light emitting device; and a protrusion disposed on at least a part of an area around the light receiving device on the output side lead frame and being formed of conductive bonding wire or a bump, protruding to the input side lead frame side.