An optical module is disclosed. The optical module includes a substrate, and at least one planar optical waveguide that includes a plurality of waveguides and at least one groove vertically penetrating the upper surface of the substrate and which is successively laminated on the substrate. The optical module also includes at least one PCB having at least one integrated photoelectric conversion device that is positioned on the planar optical waveguide facing a corresponding groove, and at least one optical connection block including a body and optical fibers embedded in the body in such a manner that both ends thereof are exposed to the lateral and upper surfaces of the body. The optical connection block is inserted into the corresponding groove of the planar optical waveguide in such a manner that both ends of the optical fibers, which have been exposed, face the waveguides and the PCBs, respectively.