In an optical transmitter-receiver module for performing optical transmission and reception by using a single-core optical fiber, a light-tight partition plate unit 506 for separation between an optical path of a transmission signal light and an optical path of a reception signal light is held between a jack section 508 for detachably holding an optical plug 240 and a light emitting/receiving unit 505 which has an LED 514 and a PD 515 positioned and fixed in place and molded in one piece. The LED 514 is located at a larger a distance in a direction of optical axis from the optical fiber than the PD 515 is. The partition plate unit 506 is urged toward the optical fiber by springs.