PURPOSE: To obtain the titled element capable of easily producing and having a high response speed and a long life in repeated use by using an electrochromic body layer of a thin film obtd. from a collidal solution contg. a mixture of one or more kinds of transition metal oxides, and by using antimonic acid as a main component of a proton or a cation supply layer.

CONSTITUTION: The transparent electrode 2 is provided with the transparent substrate 1, and the electrochromic body (EC) layer 3 obtd. from the colloidal solution is formed on said layer 2. The obtd. EC layer 3 is composed of the thin film obtd. from the collidal solution contg. one or more kinds of the transi tion metal oxides such as V2O5, MoO3 and WO3, etc. The proton supply layer 4 contg. antimonic acid as the main component is provided with the layer 3. The electrochromic display element is obtd. by forming a collecting electric body layer 7 through a reversible oxidizing substance layer 6.