Namely, when the length of the incision portion is as small as the microscale length such as the height of ridge line in fingerprint of finger pad (about 100 ??m), the space between such ridge lines (about 350 ??m), or the depth of shallow wrinkles (about 200-300 ??m), the form of the incision portion is changed to various forms including a straight line, a curve line and a wavy line.