Abstract: A variable stage type carburetor having an intake passage, a throttle valve disposed in the intake passage, and a movable vane disposed at the upstream side of the throttle valve, the movable vane being adapted to cooperate with the wall of the intake passage in constituting a variable venturi and operatively connected to the throttle valve, so as to be moved in response to the movement of the throttle valve. The carburetor further has a first vane controller adapted for displacing the movable vane in the closing direction, independently of the throttle valve, when the venturi vacuum is lowered, and a second vane controller adapted to displace the movable vane in the closing direction, also independently of the throttle valve, when the force exerted by the intake air flow on the movable vane drops below a predetermined level.