A light emitting device capable of adjusting height difference between the light emitters and optical waveguides individually and easily with high accuracy is realized. The light emitting device comprises multiple light emitters; an optical multiplexer comprising the openings of multiple optical waveguides at the incidence end for light from the multiple light emitters and the opening of an optical waveguide combining said multiple optical waveguides at the light exit end; and multiple drivers driving said multiple light emitters, respectively, along the tilt direction of a surface tilted at a given angle with respect to the surface on which said optical waveguides are formed, wherein said light emitters are provided at an angle that makes the central axes of light from said light emitters in the light emission direction parallel to the surface on which said optical waveguides are formed.