The present invention realizes an IPS liquid crystal display device which exhibits small directivity of viewing angle and high brightness. Below a pixel electrode having a comb-teeth-shaped electrode and having a laterally-extending trapezoidal profile, a planar common electrode not shown in the drawing is formed by way of an insulation film. When a video signal is applied to the pixel electrode, an electric field is generated between the pixel electrode and the common electrode via slit portions formed in the pixel electrode thus controlling liquid crystal molecules. The pixel electrodes are arranged in a packed state by alternately reversing the direction of the trapezoidal shape in the longitudinal direction. Since a light blocking film is not present between two pixel electrodes arranged adjacent to each other in the longitudinal direction, the liquid crystal display device can acquire high transmissivity. As a result, a liquid crystal display device having high brightness can be realized.