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.