To prevent fuel in a cylinder hole from overflowing from an upper end of a guide collar when a plunger is continuously operated in the cylinder hole.

This plunger type acceleration pump device for the carburetor is constituted in such a way that volume W in a guide hole formed by a guide hole 11c of the guide collar 11 and the outer periphery of an operation rod 13a is larger than or substantially equal to difference V (V1-V2) between first volume V1 of a rubber cap chamber A formed inside a rubber cap 14 at an ascent stop position of the plunger 13 and second volume V2 of the rubber cap chamber A formed inside the rubber cap 14 at a descent stop position of the plunger.