To produce negative pressure in a nozzle external-cylinder and prevent liquid drip effectively by making the outside diameter of the large-diameter part of a plunger valve equal to the inside diameter of the upper small-diameter part in the nozzle external-cylinder, and by moving the large-diameter part of the plunger valve within the small-diameter part in the nozzle external-cylinder hermetically at the time of the upward movement of the plunger valve.

A nozzle external-cylinder 3 is divided into two, an upper small- diameter part 12 and a lower large-diameter part 13, and a plunger valve 6 is comprised of a large-diameter part 17 whose outside diameter is equal in size to the inside diameter of the small-diameter part 12 of the nozzle external-cylinder 3, and a small- diameter rod part 18 that is integrated with it. A liquid filler is supplied into a filling nozzle 1 via a supply pipe 11, a cylinder 14 is actuated in synchronization with it to move the plunger valve 6 downward, thereby filling the liquid filler from a filling opening 5 via the interior of the nozzle external-cylinder 3. When the plunger valve 6 is then moved upward by the actuation of the cylinder 14, the large-diameter part 17 moves upward within the upper small-diameter part 12 of the nozzle external- cylinder 3 hermetically. As a result, negative pressure is produced in the nozzle external-cylinder 3 and liquid drip from the filling opening 5 is prevented.