To erasably display individual information about each product glass in the one corresponding thereto with reduced labor and smooth the handling of a product glass after cutting treatment even in the cutting treatment with a glass cutting machine.

When a material glass (w) is cut to plural product glasses w1 to w6 with a glass cutting machine 1 controlled on the basis of output information from a computer, individual information about each product glass is displayed on a required piece of paper with a printer 2 controlled on the basis of the output information from the computer and operations are performed so as to apply the displayed piece of paper to each of partial sites s1 to s6 of the material glass to be the product glass corresponding to the piece of paper with a stamper 3 controlled on the basis of the output information from the computer.