PURPOSE: To always keep a certain regulating force by dividing a spring of a regulating apparatus for throttle of an internal combustion engine into two regions, making spring coils contact with each other in one region, and making the spring coils spaced apart with each other in the other region.

CONSTITUTION: A shaft 4 is rotatably supported in a penetrating hole 3 of casing 1 of a regulating apparatus. A throttle valve arranged in an end of the shaft 4 is opened or closed by a lever 5 arranged in the other end of the shaft 4 and in one body with a bush 2. While the lever 5 is at rest side, the shaft 4 returns back to the rest position by returning force of a spring 7. The one end 8 of the spring 7 is supported by the casing 1 through a pin 10, and the other end is fixed on a hole 12 of the bush 2. Therefore, the spring 7 is formed having a region 27 that is equal to the big space of coil 22 and a region 24 that is equal to the small space, so the returning force and friction can independently be set up.