PURPOSE: To eliminate the manual operation for feeding paper in a feed port by mounting freely attachably and detachably a sheet feed unit to the body of a copying machine, etc. and driving said unit so as to feed sheets cooperatively with a forward and backward moving member such as an original base or the like.

CONSTITUTION: A feeder body 1 is mounted freely attachably and detachably to an image forming device 6. When the operator oscillates first a driving lever 2 around a shaft 2a just once by hand in a clockwise direction, a conveying roller 3 moves leftward along a groove 5a without being rotated by a one-way clutch 4 and feeds copying paper 12 to the inside of the device 6. When the front end of the paper 12 pushes a paper detecting lever 15, the function on the body side operates and copying for the 1st sheet is acomplished. The lever 2 is reset to the initial state during this time. The one-way clutch 4 prevents the paper 12 from being affected by the resetting of said lever. An original platen 7 projects rightward and oscillates the lever 2 prior to the end of copying and therefore the paper 12 is thereafter automatically fed cooperatively with the movement of the original platen.