An in-plane switching liquid crystal display device includes a liquid crystal display panel having first and second substrates, a first polarizer disposed at a first surface of the liquid crystal display panel and having a first protective film, a first polarizing film, and a second protective film, a second polarizer disposed at a second surface of the liquid crystal display panel and having a third protective film, a second polarizing film, and a fourth protective film, and a first optical compensation film between the first polarizer and the liquid crystal display panel, the third protective film being adjacent to the liquid crystal display panel and having a substantially zero retardation value.