According to one embodiment, a relay connector connects two input connectors respectively mounted on mounting surfaces of two substrates, ends of which are arranged to be opposed to each other. The relay connector includes a relay connector main body and relay terminals. The relay connector main body includes a substrate regulating section interposed between the ends of the two substrates and set in contact with the ends of the two substrates to form a space between the ends of the two substrates. The relay terminals project from both ends of the relay connector main body to be connected to the input connectors.