A new display device is required, which has concepts of flatness and slimness. FED can be one of the solutions. When we use flat panel, we can save the raw material and reduce the production time by eliminating the printing process, drying process, and washing process. In this case, good panel flatness and consistency with panel flatness and black matrix is the precondition. Therefor, we analyzed process capability of panel flatness and regression between panel flatness and BM position by experiments.