A light-receiving module includes: a pigtail optical fiber including a core portion for transmitting an optical signal and a cladding portion covering a side face of the core portion; an optical connector provided at a first end of the pigtail optical fiber for optically connecting a transmitting optical fiber with the end of the pigtail optical fiber; a light-receiving device having a light-receiving face for receiving the optical signal propagating through the core portion and for converting the optical signal into an electric signal; an optical coupling system for converging the optical signal emitted from a second end of the pigtail optical fiber onto the light-receiving face of the light-receiving device; and means for preventing light propagating through the cladding portion from reaching the light-receiving face of the light-receiving device so that the optical signal propagating through the core portion does not interfere with the light propagating through the cladding portion on the light-receiving face of the light-receiving device.
