Abstract: In a two-way optical communication device, a rising mirror bends light transmitted from a light-emitting element in a virtually perpendicular direction to a surface of a substrate, and the light is gathered on an end of an optical fiber via a light-gathering mirror having a curved surface and is coupled to the optical fiber. Further, in the two-way optical communication device, received light, that is propagated from the optical fiber, is reflected on the light-gathering mirror and is gathered on the light-receiving element. The two-way optical communication device can transmit and receive light through a single optical fiber, causing only small loss in transmission and reception, so that light can be efficiently coupled to an optical fiber such as a POF having a large diameter.