A device for optical communication including a conductor circuit and an insulating layer formed and laminated, an optical circuit and an optical path for transmitting an optical signal, and an optical element or a package substrate on which an optical element is mounted. An optical path converting member is disposed at the optical path for transmitting an optical signal so as to transmit an optical signal between the optical element and the optical circuit. The optical path converting member comprises a lens and an optical path conversion mirror having an entrance surface, an exit surface and a reflection surface. The lens is provided at either the entrance surface or the exit surface on the side facing the optical circuit.