To provide a highly reliable fuel injection pump which prevents an oil seal from being damaged.

Fuel for lubricating sliding parts is supplied from a feed pump 60 to a storage chamber 40 inside a housing 10 which houses a driving shaft 15, a cam 22, and a plunger 20. Excess fuel in the chamber 40 is recirculated to a fuel tank 6 through a fuel delivery passage 57 and a recirculation passage 58. If the fuel delivery passage 57 or the recirculation passage 58 is clogged for some reason and the pressure of fuel inside the chamber 40 rises, a check valve 82 opens, and the fuel in the chamber 40 recirculates through a communication passage 81 to the inlet side of the feed pump 60. Thereby, a pressure rise in the chamber 40 is avoided, preventing any damages to the oil seal 17, to which the fuel from the chamber 40 is supplied.