PURPOSE: To reduce the burden of a worker and to improve the work efficiency, by putting a hand riveter movably on a duct flange through a guide roller attached to a receiving member.

CONSTITUTION: A hand riveter 1 consisting of a press projecting piston 4 for pressing rivets and a receiving member 6 is provided with a guide roller supporting mechanism 2. This supporting mechanism 2 consists of a supporting plate 21 having a guide roller 3 attached freely rotatably by a bolt 31 and a nut 32, a movable plate 20 which is attached pivotally to the receiving member 5 by a bolt 24 and is provided with a guide hole 25, and a spring 22. When the riveter 1 is operated, the riveter 1 is supported on a duct flange (which is not shown in figure) through the guide roller 3. The movable plate 20 is slidable along the guide hole 25, and the position of the guide roller 3 is determined in accordance with the width of the duct flange, and it is held in this position by the bolt 23.