A sliding throttle valve type carburetor comprising a sliding throttle valve, an air intake passage and a fuel float chamber, the sliding throttle valve extending along a line of intersection with the intake passage and being disposed at an acute angle relative to the portion of the intake passage upstream from the sliding throttle valve. The sliding throttle valve forms an angle of intersection with the portion of the fuel surface in the float chamber upstream from the sliding throttle valve which is greater than the aforementioned acute angle.