To provide a sealing screw which exerts a nearly perfect sealing function.

A rotation handling member 4 is provided in a periphery of a rotating member 2 with a threaded part 1. This rotation handling member 4 includes a cylindrical part 4a which covers the nearly entire region of the periphery of the rotating member 2 and a covering part 4b which closes one opening of the cylindrical part 4a. Then, between the rotating member 2 and the rotation handling member 4, there is provided a rotary motion transmission mechanism for rotating the rotating member 2 and the rotation handling member 4 integrally with each other in a direction to fasten the threaded part and for rotating both the members 2 and 4 relatively to each other in a direction to loosen the threaded part 1.