To provide a apparatus for processing an object by projecting shots thereon that can be downsized and can use shots of appropriate sizes. A pressure tank 42 is disposed below a position 24X where an object to be processed 12 is projected. The shots that have been projected are received by the tank 42. The discharging portion of the tank 42 is communicated with a device for projecting shots. One end of a piping for transporting air for a discharge 54 that can suction shots is connected to a position between the position 24X and the tank 42. The other end of the piping 54 is connected to a separator 68. The separator 68 is connected to one end of the piping for transporting air for a supply 76 that can suction shots. The other end of the piping 76 is communicated with the room for projecting the shots 16.