PURPOSE: To preferentially display the display data of high importance even in the case that the abnormality of operation occurs in displayers in a display device provided with plural displayers.

CONSTITUTION: Every displayer 108 to 111 outputs a status signal 120 to 122 to show its operating state. Display controllers 104 to 106 corresponding to every displayer 108 to 110 are provided with screen memories 111 to 113, 114 to 116, 117 to 119 in which the display data to be displayed on every displayer 108 to 110 are stored, and selection circuits 126 to 128 select and output one of them in conformity to display select signals 123 to 125 from the outside. When a display selection controller 107 detects the abnormality of the operation of one of the displayers 108 to 110 by the status signals 120 to 122, it changes the state of display select signals 123 to 125 so that the display data of the high importance is displayed by using the displayer in a normal state.