To prevent sewage or the like from leaking even when the pressure of water to be charged in the vacancy of a lantern ring is not higher than that in a machine.

This device is provided with a lantern ring 4 and a gland packing 2 inserted between a stuffing box 1 and a rotating shaft 9 and pushed in with a packing retainer 3 whereas water is charged in the vacancy of the lantern ring 4 from the outside before use. A foreign matter preventing plate 5 which is mounted so as to form a sealing chamber 6 at the machine inside of the stuffing box 1 and inhibits bulky foreign matter from invading, and a rubber seal ring 7 whose cross section is of V shape and which is tightened against the rotating shaft 9 by a compression spring 8 fitted around a thread bottom part of V-shaped cross section by one turn so that one end part of the V-shaped cross section may be brought into the end surface of the stuffing box 1 in a free condition inside the seal ring chamber 6.