To reuse glass used in a flat panel display, processing suitable for global environment such as processing of separating a lead component must be realized. A disassembly processing method for a flat panel display having a structure in which a face plate and rear plate mainly containing glass are airtightly joined via a frame with frit glass is characterized by including the step of separating the face plate and rear plate joined with the frit glass. The separation step is characterized by separating the face plate and rear plate by cutting, dissolution, or melting.