PURPOSE: To safely, precisely and easily perform the cutting work of a sheet by providing an operation part having a blade facing a through-groove along a rail on a base having the through-groove in such a manner as to be capable of sliding.

CONSTITUTION: When a sheet such as film or paper is cut for sampling, a base 1 is first placed in a prescribed position on the sheet. The position of a through- groove 2 is set on the extension of a line to cut by use of a notch 3 provided on the base 1. A stopper 14 is then removed, the finger is put on a finger hook 12, and a blade 11 is pushed down into the trough-groove 2. A grip part 8 is held as the blade 11 is still pressed down in this state to move an operation part 6 along a rail 5, and the sheet is cut by the blade 11 moving in the through- groove 2 along the through-groove 2. Thus, the sheet can safely, easily and precisely be cut.