To always cut an object to be cut at a right angle relative to the object when it is cut by a mechanical cutter.

When an object 4 to be cut is put on a two-point supporting base 1, the two-point supporting base 1 is rotated and moved in the vertical direction with a rotary shaft A of the two-point supporting base 1 as a center by weight of an object to be cut 4, the two-point supporting base 1 becomes parallel to the object 4 and therefore, the object 4 becomes parallel to a receiving base of a mechanical cutting device D in the same way in also a state that the object 4 is put on the receiving base of the mechanical cutting device D put on the two-point supporting base 1. When the object 4 is cut by fastening a fixed vice of the mechanical cutting device D in this state, a cutting surface can be always cut at a right angle relative to the object 4. In this case, the two-point supporting base 1 and the mechanical cutting device D put on the supporting base 1 are balanced in weight in left and right directions with the rotary shaft A of the two-point supporting base 1 as the center.