PURPOSE: To provide an improved plunger assembly used in the case parisons are formed by a glassware forming device by constituting the plunger which comprises a metallic plunger and has a specific structure.

CONSTITUTION: The plunger assembly used for the case the parisons are formed by the glassware forming device comprises the metallic plunger 2 and the nose part 8 of the plunger 2 is provided with a small chamber 16. To use such plunger 2, water is supplied via a pipe 18 to the small chamber 16. The water of the same volume as the volume of the water is extruded via the passage in the nose part 8. The water forms a barrier of vapor between the plunger 2 and molten glass by vaporizing. The plunger 2 internally has a recessed part 4 and is cooled by the air supplied into the recessed part 4. The glassware formed from the manufactured parisons is less internally flawed and the number of the ware having flaws in the neck parts is extremely slight.