In accordance with one aspect of the present invention, an optical transceiver includes a printed-circuit board, an optical module that converts a received optical signal into an electrical signal and converts an electrical signal into a optical signal, and transmits the converted signal, the optical module being mounted on the printed-circuit board, and an edge connector that inputs and outputs the electrical signal, the edge connector being mounted on the printed-circuit board. In the optical transceiver, at least an edge portion of the edge connector is formed in a direction roughly perpendicular to the optical signal transmitted/received at the optical module, and the printed-circuit board is removably connected to the host substrate through the edge connector in such a manner that the printed-circuit is roughly perpendicular to the host substrate to be connected.