An intake electromagnetic driving valve and an exhaust electromagnetic driving valve are provided which use electromagnetic force to drive an intake valve and an exhaust valve, respectively. In step 102, the ratio between the number of combustion execution cycles and the number of combustion halts is set to obtain a desired target output value. Output control patterns that each consist of combustion execution timing equivalent to the required number of combustion execution cycles, and combustion halt timing equivalent to the required number of combustion halts are set in step 106, 114. In steps 108 to 112, or 118 to 122, in accordance with the output control patterns, whether combustion is to be executed is set with respect to the explosion timing that arrives in each cylinder in order.