To provide a fuel supply mechanism for a carburetor for suppressing excessive pulsation pressure by discharging pulsation pressure in a pulsation pressure introduction chamber of a diaphragm fuel pump to the outside.

The fuel supply mechanism for the carburetor in which fuel of a fuel tank is supplied to a constant pressure fuel chamber of the carburetor by the diaphragm fuel pump and fuel of the constant pressure fuel chamber is supplied to an intake passage of the carburetor via a fuel nozzle is characterized by partitioning the diaphragm fuel pump into the pulsation pressure introduction chamber and a pump chamber by a diaphragm, communicating the pulsation pressure introduction chamber with a crank chamber of an engine and communicating the pulsation pressure introduction chamber with the intake passage via an air vent.