PURPOSE: To clamp various cylindrical bodies having different inside diameters and also, to hermetically seal the inside of the cylindrical body.

CONSTITUTION: Each one end of plural sheets of leaf springs 11, 11, 11 is fixed to a vertically movable base flange 6 and each other end is inserted into the base flange 6 and is fixed to a tip of a rod 2 movable relatively to the base flange 6, and the rod 2 is moved in the contraction direction and the leaf spring is bent outward and an inside wall of the cylindrical body 1 is held by the bent leaf spring. An adhesive sheet 13 is stuck to a contact part of a tip opening part of the cylindrical body 1 with the base flange 6 and also an energizing means pressing a contact part with the base flange 6 is attached.