Disclination of an active matrix liquid crystal display device is reduced. Portions of pixel electrodes are formed so as to mutually overlap with a convex portion. If the height of the convex portion is too tall, the amount of light leakage increases due to liquid crystals orienting diagonally with respect to a substrate surface. (See FIG. 1C.) If the height of the convex portion is low, the disclination reduction effect is low. The optimal convex portion height is thus determined.