PURPOSE: To perform smooth exchange, attachment, and detachment of a work to and from the chuck of a lathe and a grinding machine.

CONSTITUTION: A swing arm 8 provided at its tip with a work feed chuck 13 and a take-out chuck 14 is rotatably arranged in a manner to cause the two chucks to draw the same locus as each other. A work input port 21 positioned facing the feed chuck 14 and an output port 22 positioned facing the take-out chuck 14 are respectively disposed to one end of the rotation stroke of the swing arm. A two-throw cylinder 9 comprising a piston rod 11 to revolve the take-out chuck 14 from the output port to the chuck position of a lathe or a grinding machine and a piston rod 12 to further revolve the feed chuck 13 from the position to the chuck position of the lathe or the grinding machine is coupled to the swing arm 8.