An in-vehicle charging apparatus (100) has: a charge control ECU (10), which operates with power supplied from a low-voltage battery (16), and which controls charging; an S2 switch, which is on/off controlled by means of the charge control ECU (10), and which reduces a voltage of the pulse signals when the switch is in the on-state; and a switch (SW1), which is controlled to be in an on-state by means of units other than the charge control ECU (10), and which reduces the voltage of the pulse signals when the switch is in the on-state. In the cases where the switch (SW1) is turned on, power from a charging cable (200) is supplied to the low-voltage battery (16) or the charge control ECU (10).