To prevent a user of a metal cutter from failing to close a movable cover which is closed by its own weight since its weight is large and which covers mainly the lower side of a cutting blade, by surely closing the cover by the action of its own weight even if the cover is fully opened.

An opening position restriction member 70 for returning the opening position of the movable cover 53 to the position where its center of gravity G acts to the closing side by the biasing force of a spring, is installed at the rear of a fixed cover 51.