In a semi-transmissive liquid crystal display device having a reflective region 5 and a transmissive region therein, a one-half wavelength plate 29 is disposed between a lower substrate 11 and a polarizer 21a provided on a side of the lower substrate. This makes liquid crystal molecules in at least the transmissive region 6 driven by a horizontal electric field and allows the device to operate in a normally-black mode in both the reflective region 5 and the transmissive region 6, realizing a semi-transmissive liquid crystal display device having wide viewing angle characteristics.