To provide a holding mechanism of a door which opens and closes an outlet insertion slot of a charger with a simple structure.

An electromagnet 9 is installed at a position to which an upper end part of an opening/closing door 2 moves when the opening/closing door 2 formed by a ferromagnetic body is opened. The opening/closing door 2 is attracted by using the attraction force of the electromagnet 9 to maintain the opening state of the opening/closing door 2. The structure ensures to prevent the opening/closing door 2 from interfering the insertion of a connector plug 5 when a user inserts the connector plug 5 of a power feeding cord 6 into an outlet 4.