To prevent damage to internal electrical components in a hot-plug event while minimizing increases in cost. A coin handling apparatus (1) is provided with a coin selection unit (3), a coin storage unit (2), and a harness (4). The coin storage unit (2) has a first connector (21) that includes a first terminal (TH2), a second terminal (TL1), and a first ground terminal (TG1). The coin selection unit (3) has: a second connector (31) that is connected through the harness (4) to the first connector (21) and that includes a third terminal (TH4) to which a high voltage is supplied through the first terminal (TH2), a fourth terminal (TL2) for supplying a low voltage to the second terminal (TL1), and a second ground terminal (TG2) grounded through the first ground terminal (TG1); a low voltage power supply circuit (32) that generates a low voltage from the high voltage supplied to the third terminal (TH4) and outputs the low voltage from a low voltage output terminal (32t); and a switch circuit (34). The switch circuit (34) breaks the electrical connection between the low voltage output terminal (32t) and the fourth terminal (TL2) when the difference in voltage between the second ground terminal (TG2) and the low voltage output terminal (32t) is less than a threshold value.