Abstract: A plunger supporting mechanism includes a bottom mold into which a gob is loaded; a plunger which is arranged above the bottom mold, and which is lowered to pressure the gob in the bottom mold to press the gob into a glass product, the plunger having an upper portion provided with a flange; a floating unit which supports the flange in a floating manner to support the plunger so as to be movable in a horizontal direction; and a press machine for raising and lowering the plunger through the floating unit; wherein the floating unit is supported so as to be tiltable with respect to the press machine, or the plunger is supported so as to be tiltable with respect to the flange.