An IPS-method liquid crystal display device which exhibits small directivity of a viewing angle and high brightness is realized. A planar common electrode is arranged below a pixel electrode which includes comb-teeth-shaped electrodes and slits. When a video signal is applied to the pixel electrode, an electric field is generated between the pixel electrode and the common electrode by way of slit portions formed in the pixel electrode thus controlling liquid crystal molecules. To reduce the occurrence of a phenomenon that an abnormal domain is generated in an end portion of the slit and the abnormal domain lowers transmissivity of liquid crystal, the structure in which the slits having both ends thereof closed and the slits having one-side end portion thereof opened are alternately arranged next to each other in parallel is adopted.