To prevent damage to an installed member.

A case 3 is integrated with a handle part 1. The case 3 is mounted with a pivoted cartridge body 7 of a cartridge 5. The cartridge body 7 has a protective member 6 at the tip. A lid 11 is pivoted on the case 3. A leaf spring 12 is fixed at one end to the case 3 and is pressed at the other on the top surface of the lid 11. A blade 13 is fixed at the tip of the case 3. The protective member 6 has on the lower portion a projection 23 whose bottom is inclined up from the bottom of the cartridge 5.