An engine includes variable valve mechanisms capable of causing an intake valve and an exhaust valve to stop. An ECU estimates poisoning states of catalysts, and executes and prohibits stopping of the valves based on the poisoning states. When stopping of the valves is prohibited during a fuel-cut operation, the ECU drives a crankshaft of the engine by means of a motor to idle the engine. Thus, even in a hybrid vehicle in which the engine is stopped during a fuel-cut operation, a sufficient amount of oxygen can be rapidly supplied to the catalysts by utilizing a pumping action of pistons, and the catalysts can be caused to recover from rich poisoning efficiently.