To cut the residual parts such as a sprue, a weir or the like from a casting without giving damage to a workpiece and a cutting machine.

Regarding the casting residual part cutting device 1, the lower face of a beam member 4 is provided with guide rail receivers 21, 22 fitted to two strips of guide rails 11, 12 installed downward, and a saw rotating shaft 41 and a motor 42 are erected on the upper face of a moving body 20 horizontally moving in a suspended state by a screw feeding mechanism. Further, the device is provided with a clamping apparatus 56 for fixing a workpiece W made by casting to the side of the surface 53 in the vicinity of the left edge of a workpiece installing plate 52 rotating with a spindle 51 parallel to the guide rails 11, 12 as the center of rotation, and to the side of the rear face 55 in the vicinity of the right edge, and, in a state where the workpiece installing plate 52 is horizontally rotated and stopped, the workpiece W made by casting on the side of a circular saw 3 is made into a state set in such a manner that, with a residual part W1 downward, the root of a residual part W1 becomes a cutting height within a cuttable range by the circular saw 3.