To provide a cutter finely finishing a cut surface when cutting a thin workpiece.

In the cutter A, an upper cutting blade (a moving cutting blade) 2 is crossed against a lower cutting blade (a fixed cutting blade) 1 to cut a thin workpiece W. The cutter is provided with: the lower cutting blade 1 held on a table 31 of a machine base 3; the upper cutting blade 2 held above the machine base 3 with a prescribed shear angle and provided so as to move down while swinging; and a workpiece pressing mechanism 9 provided inside the upper cutting blade 2 to press down the thin workpiece W conveyed onto the table 31. In a state where the workpiece W is pressed down by the workpiece pressing mechanism 9 to be stopped moving, the upper cutting blade 2 is moved down while swinging, and a blade edge of the upper cutting blade 2 is crossed against the lower cutting blade 1 at an angle. While gradually decreasing a cut angle of the upper cutting blade 2, the workpiece W is cut in a pulling manner from one end to the other one by one.