PURPOSE: To lessen the lowering of an opening rate by setting the area that a spare switching element occupies on a substrate smaller than the area that a switching element occupies.
CONSTITUTION: The area that the spare switching element 4 occupies on the substrate is set smaller than the area that the switching element 3 occupies. The length in the extending direction of a gate bus stay 8 of a spare TFT 4 formed on a gate bus stay 8 is set at 1/2 that of a TFT 3. The widths of the TFT 3 and the spare TFT 4 are equal and, therefore, the area that the spare TFT 4 occupies on this substrate is half the area that the TFT 3 occupies on the substrate. The picture element defect by the defect of the switching element is corrected in this way and the lowering of the opening rate is lessened.