To reduce the manufacturing cost of fuel pressure pumps by facilitating their assembly or facilitating the insertion of pump cams integrated with valve system camshafts into pump-body cam chambers.

A pump body 1 includes a cylinder 5 for accommodating a plunger 4, and a cam chamber 6 to which one end of the cylinder 5 opens. A pump cam 3 integrated with a valve system camshaft 2 of an engine body is inserted in the cam chamber 6 when the pump body 1 is installed in position in the engine body. The pump body 1 has in its outer wall an insertion hole 12, in which such a pusher jig as a pin 13 is inserted as the pump body 1 is attached to the engine body. The jig forces up the plunger 4 and other related components to a height free of contact with the pump cam 3, which is therefore allowed to enter the cam chamber 6.