An optical module includes a circuit board, an optical element mounted on the circuit board, an electronic parts for driving the optical element, an optical block optically coupled with the optical element and adapted to be connected to an optical connector, wherein the optical block includes a protrusion including a guide pin for connecting the optical block to the optical connector, and a receiving portion formed nearly cylindrical around a root of the guide pin and having a receiving surface on which the optical block abuts the optical connector, an optical block reinforcing member including an upper lid for covering the optical block, and sidewalls for covering both sides of the optical block arranged perpendicular to a width direction of the optical connector, wherein the optical block reinforcing member includes a separate body from the optical block and is adapted to be attached on the optical block, and a casing for housing the circuit board, the optical element, the electronic parts, the optical block and the optical block reinforcing member.