To provide a starting device for a carburetor to perform smooth acceleration operation during acceleration operation wherein a throttle valve is released just after starting operation.

A starting fuel passage 19 connected to a fuel source a starting air-fuel mixture passage 21 connected to an intake passage 2A on the engine side from a throttle valve 3, and a starting air passage 20 are opened to a starting valve guide cylinder 18. Opening and closing of an opening to the starting guide inner cylinder 18 for the passages 19, 20, and 21 are controlled by a starting valve 22. The upper stream opening 20A of the starting air passage 20 is opened to a venturi part V formed on the air cleaner side by the throttle valve 3.