An optical transmitter includes an optical device, a wiring board including a first main surface and a second main surface, the optical device being mounted at a position closer to the second main surface than to the first main surface, a holding member fixed to the wiring board, at a position closer to the first main surface than to the second main surface, and an optical fiber inserted into a through hole of the holding member, where the wiring board includes a wiring pattern of a wiring layer sandwiched between an upper insulating layer and a lower insulating layer, and further includes an opening from which an upper surface and a lower surface of the wiring pattern are exposed, and an end surface of the optical fiber is in contact with the upper surface, and an external electrode of the optical device is bonded to the lower surface.
