To provide a work supply device of a machine tool having a small and simple device structure and capable of mechanically and highly accurately drive controlling of mutual actuators of a loading part and an unloading part.

By adopting this cam device 1 having the structure for intermittently, reciprocatably and linearly operating a pair of driven cams 6 and 7 by a single rotational driving cam 5 as a driving part of the work supply device, an operation area of the loading part 35 and the unloading part 36 of the work supply device is reduced, the installing space can be reduced, and the driving of the mutual actuators of these both parts 35 and 36 can be mechanically and highly accurately controlled.