To provide a double-barrel carburetor capable of simplifying the configuration of a fuel passage to reduce mechanical machining, reducing costs, and preventing the occurrence of dieseling when an engine stops.

A carburetor body 1 having a pair of parallel right and left suction passages 2 and a fixed fuel chamber 30 are integrally constituted. One high speed fuel passage 67 and one low speed fuel passage 54 are provided in a wall part between the pair of suction passages 2 from a central part of the fixed fuel chamber 30 via a high speed fuel jet 74. The high speed fuel passage 67 is branched into two passages on the lower face of the carburetor body 1 and is communicated with a high speed fuel injection hole 5 in the venturi part 2a of each suction passage 2 on the right and left sides. The low speed fuel passage 54 is extended to the vicinity of the upper end of the carburetor body 1 via the wall part between the suction passages 2, is branched into two branch passages 51 via a low speed fuel jet 54a on the halfway of the low speed fuel passage 54, and is communicated with a low speed fuel injection hole 6 in the vicinity of the close position of a throttle valve 9a of each suction passage 2 on the right and left sides. A solenoid opening and closing valve 41 opening and closing the high speed fuel jet 74 is provided in the lower part of the fixed fuel chamber 30.