It is an object to provide a liquid crystal display device including a thin film transistor with high electric characteristics and high reliability. As for a liquid crystal display device including an inverted staggered thin film transistor of a channel stop type, the inverted staggered thin film transistor includes a gate electrode, a gate insulating film over the gate electrode, a microcrystalline semiconductor film including a channel formation region over the gate insulating film, a buffer layer over the microcrystalline semiconductor film, and a channel protective layer which is formed over the buffer layer so as to overlap with the channel formation region of the microcrystalline semiconductor film.