To make a charger current zero during use of a portable telephone set by firmly fitting a push-button switch which opens and closes the main power source to the AC charger of the telephone set to an attachment code.

The attachment plug 6 of an AC charger 1 is inserted into the socket cap 8 of an attachment cord 7 and one line of the cord 7 is branched in the state 9 and 10 and connected to a push-button switch 3. The switch 3 is fitted to a small-sized L-shaped board 5 and the board 5 is fixed to the upper surface of the charger 1. When a portable telephone set 2 is set on the charger 1, the back section 4 of the telephone set 2 presses the switch 3 and power supply is made to the charger 1. When the power supply is made, the charger 1 operates and a prescribed charged state is set. When the telephone set 2 is removed from the charger 1 thereafter, the switch 3 is opened and turns off a circuit and the current of the main power supply to the charger 1 becomes zero. Therefore, energy consumption can be saves by only attaching and detaching the telephone set 2 to and from the charger 1 without attaching/ detaching the attachment plug 6.