PURPOSE: To certainly recover upper burr by squeezing the upper burr fitted to the leading end of a blow pin by an extraction means to leave the same in a duct and recovering the upper burr by air.

CONSTITUTION: When a holder J is closed to hold a hollow molding, the duct 1 and extraction plate 110 as well as chuter 2 and an extraction plate 120 of an upper burr recovery device cooperate with each other. At this time, a probe pin H1 becomes the state inserted in a blow pin extraction hole. Next, when the blow pin H1 is raised, the upper burr B fitted to the blow pin H1 is also raised. The upper burr B is squeezed by the extraction plates 110, 120 to be left in the duct 1 and the chuter 2. The hollow product M from which the upper burr B is removed remains in the holder J.