Abstract: A plug receptacle includes a housing having at least one outlet unit to which a plug is adapted to be connected to supply a DC power to the plug, and a cable, connected to the housing, for supplying the DC power to the housing. The outlet unit includes a plug-receiving portion having a plurality of substantially circular pin-inserting holes into which plug pins of the plug are inserted and an insertion groove formed to surround a periphery of the plug-receiving portion. The plug-receiving portion has a substantially quadrangular shape viewed from a front side thereof. The insertion groove is adapted to receive a surrounding wall of the plug and has a substantially quadrangular shape viewed from the front side. The pin-receiving holes are arranged along one side of the plug-receiving portion serving as a reference side and offset closer to the reference side than an opposite side to the reference side.