To restrain hunting of engine rotation by reducing the oscillating amplitude of a fuel flow control rack smaller than the case of directly interlocking and connecting the fuel flow control rack by extending a governor lever even when a governor sleeve is oscillated in the sliding direction.

A fuel flow control rack 5 is interlocked and connected to a governor lever 3 through a junction lever 6 by interposing the junction lever 6 free to oscillate between the governor lever 3 and the fuel flow control rack 5 in a mechanical governor of a diesel engine. Thereafter, a transmission ratio of the fuel flow control rack 5 by a governor sleeve 2 is reduced smaller than the case of directly interlocking and connecting the fuel flow control rack 5 to this governor lever 3 by extending the governor lever 3.