An optical antenna includes an optical element mount (3) for mounting fiber ends (1a and 2a) of optical fibers (1 and 2) at different positions; and an optical transmitting and receiving system (4) for collimating, when laser beams are radiated from the fiber ends (1a and 2a), the laser beams to parallel light rays toward the space, and for focusing, when laser beams arrive from the space, the laser beams onto the fiber ends (1a and 2a) This makes it possible to set two optical transmitting and receiving directions 5 and 6 without installing complicated mechanical elements.