PURPOSE: To correct the operation cycle of an engine easily and securely by opening and closing the first intake valve for 4-cycle and the second intake valve for 2-cycle by a solenoid valve driving device.

CONSTITUTION: This device is composed of an intake valve 1 for 4-cycle positioned in an intake port 11 and an exhaust valve 2 positioned in an exhaust port 22 formed in a cylinder head 3, an intake valve for 2-cycle positioned in an intake port 9 formed at the lower portion of the cylinder, and a valve lifter 10 for opening and closing these valves 1, 2, and 5 by electromagnetic force. The valve lifter 10 is controlled by the controller 15 to operate either of the intake valves 1 and 5 and keep the other valve closed. Thus, the operation of an engine can be converted to 4-cycle or 2-cycle easily and securely.