PURPOSE: To provide a cutter for wall paper or a carpet capable of being simply adjusted for its cutting edge while it is mounted on the wall paper or the carpet.

CONSTITUTION: A bottom plate 2 provided with a slide shaft 7 on the upper face, a main body 1 having a guide hole 9 reciprocatably inserted with the slide shaft 7 from the bottom face and holding a cutter 5, a feed screw system 8 reciprocatively driving the slide shaft 7, and an operating tool 4 operating the feed screw system 8 are provided. The screw shaft 8a of the feed screw system 8 is rotatably inserted into the main body 1, an insertion hole 10 communicating the guide hole 9 to the outside of the upper side of the main body 1 is formed, and the operating tool 4 is assembled to a screw shaft 8a protruded from the insertion hole 10 on the upper side of the main body 1.