To effectively collapse and drop down molding sand hardened in the deep position of a casting by hitting the casting with a hammer indirectly combined with a supporting member while vibrating the supporting member fixing the casting.

The casting 31 is fixed to the supporting member 23. The hammer means 43 is fitted to the supporting member 23 through a lateral plate 32, elastic body 41 and gantry frame 42. The vibrating means 24 acts the vibration having a conveyability to the casting 31 through the supporting member 23. At the same time of the vibration, the shaking vibration is forcibly added to the casting 31 with the hammer means 43 acted with the compressed air. The molding sand, such as a core, is surely collapsed and discharged to the outer part of the casting 31. The molding sand stuck to the surface of the casting 31 is surely separated with two kinds of the vibrations. The sand dropped down on a receiving plate 23, is dropped down into a receiving box from a chuter with the conveyability of the vibrating means 24. The hitting reaction of the hammer means 43 is absorbed in the deformation of the elastic body 41 and the breakage at the stress concentrated position is prevented.