To provide a small-sized automatic interrupting device for friction clutch.

This automatic interrupting device 1 for friction clutch decelerates turning force of a motor 2 by a decelerating mechanism 3 and rotates a crank 4 for having an output rod 6 moved axially to interrupt a friction clutch. A spring-type accumulator 7 connected with the crank 4 via a link 5 accumulates force via the crank 4 and the link 5 from the output rod 6 that receives pushing pressure from a piston rod of a hydraulic cylinder at the time of connecting the friction clutch for moving axially to a direction of an arrow (a) and releases accumulated pressure to the crank 4 via the link 5 at the time of releasing the friction clutch to support the output rod 6 to move axially to a direction of an arrow (b). Consequently the accumulator 7 does not need an oscillating space as for a conventional automatic interrupting device for friction clutch. Thus the automatic interrupting device for friction clutch 1 can be small-sized.