To provide a cutter mounting/removing jig capable of easily mounting or removing a cutter on the cutter mounting part of a cutter device.

This jig is provided with a substrate 11, a supporting point part 12 fixed to the upper surface of this substrate 11 and a jig main body 13 which is freely rotatably supported in the midway part by this supporting part 12 and is capable of rotating in the vertical direction by making the supporting point 12 a supporting point. By providing a holding part 14 which is engaged to a cutter 3 from the lower direction and holds the cutter 3 on one end part of the jig main body 13, holding the cutter 3 by the holding part 14 and rotating the jig main body 13 by making the supporting part 12 a supporting point, the cutter 3 is elevated and lowered by elevating and lowering the holding part 14 and thereby the mounting/removing work of the cutter 3 is easily performed.