To generate a resisting force proportional to the operation speed of an input operation unit, to reduce the number of part items, and to provide a sufficiently direct feeling for touching felt by a finger tip.

This resisting force generator 1 causes the trigger of an operation device for inputting information to a game machine main body to generate a resisting force against an input operation according to game information. In this case, the device is provided with a container 54 containing magnetic powder 56, a rotary blade 57 disposed in the container 54 and rotated based on the input operation of the trigger, and an electromagnet 55 for generating a magnetic field in the container 54 according to the game information.