To realize a remote control of a throttle valve by connecting an electromagnetic actuator to the throttle valve.

A piston throttle valve 48 is inserted moveably in a vertical direction into a cylindrical valve chamber 57 that runs across an intake passage 64 of a main body 55. A fuel adjusting needle valve 59 supported at the lower end of the piston throttle valve 48 is inserted into a fuel nozzle that projects into the intake passage 64 from a fuel chamber 65 in the lower part of the main body 55. The upper end of the piston throttle valve 48 is connected to a plunger 5 of an electromagnetic actuator 10 supported on the upper part of the main body 55.