An optical reception device realizes stabilization of reception sensitivity inexpensively and highly precisely. The optical reception device comprises a Mach-Zehnder type 1-bit delay unit including a one-terminal input port and two-terminal output ports for decoding an optical difference phase shift keying (DPSK) signal and provided with one or more phase control functions to control the phase state of a light, photoelectric conversion means for branching a portion of an optical output signal outputted from the one-side output port of the Mach-Zehnder type 1-bit delay unit, to convert the branched portion into an electric signal, and a phase control unit for controlling the phase state of the Mach-Zehnder type 1-bit delay device by using the output signal of the photoelectric conversion means as an error signal.
