The present invention provides a liquid crystal display device in which display defects and reduction in the voltage holding ratio are not likely to occur even without alignment films. That is, the liquid crystal display device of the present invention includes: a pair of substrates each substantially having no alignment film; a liquid crystal layer which is disposed between the pair of substrates and contains a liquid crystal material; and a polymer layer which is formed on a surface of at least one of the substrates and controls alignment of liquid crystal molecules, the polymer layer being formed by polymerization of one or more kinds of radical polymerizable monomers added to the liquid crystal layer, at least one kind of the radical polymerizable monomers being a compound generating radicals through a self-cleavage reaction by exposure to light and having at least two radical polymerizable groups.