PURPOSE: To correctly measure fuel quantity with a simple structure by connecting a fuel supply passage that is connected to extrusion chamber of a feed pump with the way between an electronic control valve and a fuel pool, while arranging the electronic control valve in the way of fuel supply passage that connects a pump working chamber to the fuel pool.

CONSTITUTION: A radial piston injection pump has a pump piston 3 that works in combination with a cam ring 14 to reciprocate, and it supplies the fuel pressurized in the pump working chamber 5 to an injection valve 33 through a feed pipe 32 with a distributor 2. The not injected remainder fuel is guided to a fuel pool 16 built in a movable wall 17 through a fuel passage 15 attached with an electronic control device valve 21. In this case, a fuel supply passage 29 is branched and connected to the way between the electronic control device valve 21 and the fuel pool 16 in the passage 15, and the other end of the passage 29 is connected to extrusion chamber 26 of a feed pump 23. While the movable wall 17 of the fuel pool 16 opens a load reducing hole 19, a one way valve 30 is opened to supply the fuel to the pump working chamber 5.