A device for optical communication including a multilayer print circuit
board in which a conductor circuit, an insulating layer, an optical
circuit and an optical path for transmitting an optical signal are
formed, and a package substrate having an optical element or an
insulating layer and mounted on the multilayer print circuit board. An
optical path converting member is disposed at the optical path to
transmit an optical signal between the optical element and the optical
circuit. The optical path converting member includes a lens and an
optical path conversion mirror having an entrance surface, an exit
surface and a reflection surface. The lens is provided at the entrance
surface, the exit surface, or inside of the optical path conversion
mirror.