PURPOSE: To obtain proper display color and high operation stability, by using a solution having dessolved a specific organic material and a support electrolyte and electrode substrates sandwiching the solution.

CONSTITUTION: The aimed display device comprising the electrochromic solution 5 having dissolved a compound shown by the formula (R1 is H, alkyl, or aralkyl; R2, R3, R4, and R5 are H, alkyl, aralkyl, aryl, or cycloalkyl; in R1WR5, alkyl chain or aryl ring may be replaced) as an organic material capable of coloring and losing its color electrochemically reversibly and a support electrolyte, and a pair of the electrode plates 3 and 4 to sandwich the solution. The concentration of the organic material and the support electrolyte are preferably 0.01W1.0mol/l.