To continuously actuate an internal combustion engine even if a choke valve is closed as it is after the internal combustion engine is actuated by occupying the same starting position in an intake air duct at cold start time and ward shart time by the choke valve, and supplying combustion air of a quantity of a degree of maintaining an actuating condition after the internal combustion engine is actuated.

An internal combustion engine is arranged in a housing, and an ignitable air-fuel mixture is supplied to the internal combustion engine through a diaphragm carburetor 7. A starter 6 cooperates with a choke valve 11 and a throttle valve 12 rotatably arranged in an intake air duct 10 of the diaphragm carburetor 7 through a bar. An operation button 1 of the starter 6 is arranged in a gripping area of a rear grip. The starter 6 is arranged in the housing, and is used to stop the internal combustion engine by short- circuiting an igniter, and allocates a prescribed rotary position in the intake air duct 10 to the choke valve 11 and the throttle valve 12 in a starting position. Therefore, though the choke valve is closed, actuation can be maintained.