To realize the simplification in a constitution of a clutch device 1, which switches a connection state to transmit rotational power between a first rotating shaft 2 and a second rotating shaft 3 and a disconnection state not to transmit it, and the cost reduction.

Centrifugal friction members 10, 11, which are operated corresponding to the magnitude of centrifugal force, are made to automatically execute the operation of whether rotational resistance is imparted to a control member 4 or not in order to switch the connection state and the disconnection state. By this, the constitution can be made simpler compared with the conventional electromagnetic brake, and at the same time, a device and power for controlling operations of the electromagnetic brake are not required.