To provide an optical receiver that eliminates the need for strict optical axis alignment, can carry out data communication even when the optical axis is deviated in an optical space transmission system and whereby a terminal with the optical receiver can be downsized, low-profiled, and light-weighted.

The optical receiver includes: a chirp grating with a grating period changed continuously and causing optical input coupling with a light beam at an optional incident angle; an optical guide path for propagating the light beam caused with the optical input coupling by the chirp grating; and a light receiving element for converting the light beam propagated from the optical guide path into an electric signal.