PURPOSE: To obtain the injection timing adjusting device of a distributor type fuel-injection pump having a flat characteristic for reducing an acceleration noise in the intermediate speed zone of an internal combustion engine.

CONSTITUTION: In an initial delay angle state shown on a ficture, a servovalve member 9 in a bushing 8 is pushed in a right direction on a picture against a first compression spring 12 when the pressure of a through hole 23 is increased and the through hole 23 is communicated with the through hole 36 of the bushing 8 and the pressure of a pressure room 37 formed in the cover 4 side of a timer piston 7 is risen through a through hole 24. Then, the timer piston 7 is moved in the right direction on a picture against an outer spring 11. Even if the number of revolutions of a pump is increased after contacting the valve stopper 13 of a servovalve member 9 and the pressure in a pressure room 37 rises following that, the timer piston 7 is held on its advance angle position until reaching a certain pressure value.