To increase filling efficiency and filling accuracy of a filler to a joint by advancing a piston by supplying compressed air, pushing a seal package installed in a case by a push rod, and pushing out the filler in it.

A seal package 3 is set in a seal package installing case 2, and a first ventilating pipe 8 is connected to a compressor, and a valve is set in a first switching position by operating a lever 11. The compressor is started, and when compressed air is sent and supplied to a rear chamber 6 from a first air supply passage, a piston 4 advances, and its push rod 7 presses the seal package 3, and pushes out a filler in it. A pushing-out quantity of the filler is performed by controlling opening of the first air supply passage by rotating the valve by the lever 11. At this time, the air pushed out of a front chamber 5 according to an advance of the piston 4 is discharged from a first exhaust passage. When filling of the filler to a joint finishes, the lever 11 is returned to an intermediate position of first and second switching positions.