PURPOSE: To prevent an image from deforming and interference fringes from being generated by providing a couple of front and rear glass plates whose opposite surfaces are coated with a transparent conductive film, liquid crystal charged in the gap between the glass plates, a convex mirror arranged behind the rear glass plate, and a reflecting mirror which covers the back surface of the convex mirror.

CONSTITUTION: A mirror consists of a spacer 4 which holds the two parallel glass plates 2 and 3 at a proper interval and seals their peripheries, the liquid crystal 5 which is charged in their sealed gap, transparent conductive films 6, and 7 which cover the opposite surfaces of the glass plates 2 and 3 and are connected to an electric power source 10 through a switch 11, the convex mirror 26 which is arranged behind the rear glass plate 3 across the spacer 25, the reflecting film 27 which covers the back surface of the convex mirror 26, etc. Namely, the interval between the transparent conductive films 6 and 7, i.e. the thickness of the liquid crystal 5 is easily set almost equal in the liquid crystal cell of plane plate structure on the whole to prevent an image from deforming and interference fringes, etc., from being generated.