A liquid crystal display device wherein a nematic liquid crystal having a positive dielectric anisotropy and added with a chiral material is sealed between a pair of upper and lower substrates so as to constitute a helical structure twisted within a range between 140.degree. and 250.degree. along a direction of thickness thereof, and polarizing axes or absorption axes of a pair of polarizing plates disposed on the upper and lower substrates are angularly displaced by a predetermined angle or predetermined angles from major axes of liquid crystal molecules adjacent to the upper and lower substrates, respectively, and a ratio of thickness of the nematic liquid crystal to a natural molecular helical pitch of the nematic liquid crystal added with a chiral material falls within a range of from 0.14 to 0.60 inclusive.