PURPOSE: To make it possible to easily increase the gradation number of halftone so as to display high quality picture in the halftone control with pulse number modulation by constructing one picture element for display with respective discharge cells piled up in one column in laminated display panels.

CONSTITUTION: A display panel P1 is constructed so as that the discharge cell groups 61W81 of which consist of respective crossed portions of scanning electrode group Y11,12,... to which scanning signals are supplied and data electrode group X11,12,... to which display data signals are supplied arranged in a matrix, and display panels P1WP2 are laminated to construct one picture element for display with respective discharge cells 6W8 piled up in one column. As the result, the display gradation number of respective picture elements 6W8 can be presented as the sum of the display gradation number of respective discharge cells 61W81, 62W82 of display panels P1 and P2, and when the halftone is controlled with pulse number modulation, the pulse duration of the scanning signals to access one row of respective display panels P1, P2 can be elongated to several times than that in the case of one display panel to drive in low velocity. Thereby the gradation number of the halftone can be easily increased to obtain high quality display.