A power tool capable of preventing entrance of foreign matter or water etc. through the air hole as much as possible is provided. To prevent foreign matter from entering a housing 2 through a outlet 22, a first through hole 70b penetrating a main wall 71 is formed on a part of the main wall 71 of a cover 70 covering the outlet 22, second through holes 70c are formed on: a part closest to a front end portion of the cover 70; an end portion in the extending direction of the handle of the cover 70; and an end portion in the opposite direction to the extending direction of the handle of the cover 70.