A control device of a vehicle which device makes a generated voltage of an alternator variable so that a state of charge SOC of a battery installed in the vehicle reaches a control target includes an idle stop permitting SOC setting unit for setting a battery state of charge SOC in which idle stop is permissible, and a battery SOC adjusting unit for reducing and resetting a control target of the battery state of charge SOC in a range beyond the idle stop permitting SOC when a predetermined operation condition holds.