Workpiece processing apparatus and method for processing workpiece

A workpiece processing apparatus comprising:

• a cabinet having a projection chamber, a plurality of workpieces being subjected to processing in the projection chamber;
• a projector configured to project projection media toward the plurality of workpieces charged into the projection chamber;
• an image sensor configured to image the projection chamber to form an image;
• and
• a control unit configured to output information relating to presence or absence of a residue in the projection chamber based on an initial image and an inspection image, the initial image being an image formed by the image sensor and being an image of the projection chamber with no workpiece remaining, the inspection image being an image formed by the image sensor and being an image of the projection chamber after discharging processing in which the plurality of workpieces are discharged from the projection chamber,
• wherein the control unit stores at least either one of operation information of the workpiece processing apparatus in a storage device in association with the inspection image or processing information of the plurality of workpieces in the storage device in association with the inspection image.