With regard to an IPS liquid crystal display device in which a phase difference film is used as a polarizing plate protection film at the liquid crystal cell side of a polarizing plate, which is arranged at the viewing side of IPS liquid crystal cell, to provide a means for improving the re-workability of the phase difference film at production of the display device.The IPS mode liquid crystal display device according to the present invention has an IPS mode liquid crystal cell and a first polarizing plate and a second polarizing plate, which sandwich the IPS mode liquid crystal cell. Further, the first polarizing plate is positioned at the viewing side of the liquid crystal cell and is provided from the viewing side with a first polarizing plate protection film, a polarizer, and a second polarizing plate protection film; the second polarizing plate is positioned at the reverse side from the viewing side of the liquid crystal cell and is provided from the viewing side with a third polarizing plate protection film, a polarizer, and a fourth polarizing plate protection film; the second polarizing plate protection film has a film thickness of 30 to 60 μm and has a structure resulting from laminating a first optically anisotropic layer, which contains a polymer having a positive intrinsic birefringence, and a second optically anisotropic layer, which contains a polymer having a negative intrinsic birefringence; and the film thickness of the first polarizing plate protection film, the third polarizing plate protection film, and the fourth polarizing plate protection film are each 10 to 30 μm.