To provide a grinding wheel detachment/attachment supporting device stably and efficiently detaching and attaching a grinding wheel to a grinding wheel shaft.

In this grinding wheel detachment/attachment supporting device 18, a first arm 28 is supported on a vertical support shaft 27 to be freely rotatable in the horizontal plane in the center position. A pair of second arms 29 are supported on the first arm 28 at both ends to be freely rotatable in the horizontal plane at the base end. A pair of third arms 31 are supported on the second arms 29 at the ends to be freely rotatable in the horizontal plane at the base ends. A pair of holding members 33 holding a grinding wheel 17 are attached to the ends of the respective third arms 31. The supporting device comprises a lifting mechanism 34 for manually lifting each holding member 33 and for locking each holding member in the upper position so that each holding member cannot be lowered.