FUEL FEED PUMP

A fuel supply pump, which is simple in construction and easy to produce and is capable of efficiently pressurizing a high flow rate of fuel, is provided. The fuel supply pump (50) includes a housing (52), a plunger barrel (53), a plunger (54) for pressurizing fuel, which is installed in the plunger barrel (53) so as to be allowed to move up and down, a cam (60) installed in rotation way below the plunger (54), a tappet structure body (6) installed between the cam (60) and the plunger (54) to transmitting the turning force, serving as a lifting force, from the cam shaft (3) to the plunger (54), a tappet structure body (6) installed between the cam (60) and the plunger (54) and provided for transmitting a upward or downward movement of the cam (60) caused by the rotation of the cam shaft (3) to the plunger (54); and a return spring (68) for setting lowering force to the plunger (54), which is installed between the tappet structure body (6) and the plunger barrel (53).