Abstract: A cordless instrument (20, 40) detachable from a charger (10, 30, 31) is attached to the charger (10, 30, 31), and is charged. A first storage part (12, 33) chargeable from a direct current source (11, 32) included in the charger (10, 30, 31), a first charge and discharge control circuit (13, 50) to control charge and discharge of the first storage part (12, 33), a second storage part (21, 43) included in the cordless instrument (20, 40), and a second charge and discharge control circuit (22, 45) to control charge and discharge of the second storage part (21, 43) are provided. Further, a third storage part (28) chargeable from the direct current source (11, 32) may be provided. Also to the cordless instrument (20, 40), a fourth storage part (44) may be provided. Upon attaching the cordless instrument, the second storage part (21, 43) is charged at least from the first storage part (12, 33).