Abstract: A friction driving device for film developing machines which comprises a number of side-by-side film supporting roller members each consisting of a cylindrical body provided with equally spaced apart flanges defining therebetween a driving surface, and a driving roller member. The supporting rollers are so arranged as to contact the driving roller upon a drawing action exerted on the film. The driving roller member comprises a sequence of equally spaced apart cylindrical body portions of larger diameter with alternately equally spaced apart cylindrical body portions of smaller diameter having width approximately equal to the width of the driving surface of the supporting rollers and an outside diameter smaller than the diameter of the cylindrical body diameter of the driving surface of the supporting rollers.