A vacuum-adhesion attachment for a power tool includes an attachment main body, a vacuum pump, a suction part, and a valve. The attachment main body is detachably mountable on a tool main body of the power tool and houses the vacuum pump. The suction part has a chamber in fluid communication with the vacuum pump and is configured to be adhered to a surface of a work material in response to the chamber being brought to a reduced pressure state by driving of the vacuum pump. The valve is in fluid communication with the chamber of the suction part. The valve, which is normally in a closed state to block a flow of outside air into the chamber, is configured to be manually switched by a user to an open state that permits a flow of outside air into the chamber.