PURPOSE: To obtain the titled calking gun excellent in safety and processing equipped with a rack which hardly gets out of order, by covering the beak surface of the teeth of a rack body with a U-shaped sheeth, and fixing it into a unitary body.

CONSTITUTION: The main body 4 of a rack is covered with a rack sheeth 5. The positioning of the rack inside the calking gun can be performed with the outer surface of the rack sheeth 5, and the inclusion of foreign matter in the toothed surface of the rack can be inhibited, too. Hence, the calking gun excellent in safety and processing is obtained.