PURPOSE: To effectively continue a digital display in safety by providing a digital display part which indicates a different color or blinking method according to the strength of an input analog signal.

CONSTITUTION: The digital display device is equipped with an analog input part 1 which inputs the analog signal, an analog/digital conversion part 2 which converts the analog signal inputted to the analog input part 1 into a digital signal, an analog judgement part 3 which compares the analog signal with a previously determined set value, and the digital display part 4 which displays the digital signal in the different color or by the different blinking method. In this case, a blinking display is made while a digital display period is switched according to whether a specific range is entered or not in addition to a bicolor digital display of whether the analog signal is within the specific range or not, so the visual ability is prevented from decreasing even when a monochromatic digital display is deviated from the specific range.