To inspect a defect of a drive substrate such as destruction of a thin film transistor(TFT) and a short circuit of a pixel electrode, etc., even in the state without being sealed with a liquid crystal by image processing an output signal and detecting a defective pixel in the drive substrate.

This device is provided with a switching means 7 connected to a video input part 4, an inspection signal generation means 8 connected to the terminal A of the switching means 7, an I/V amplifier 9 as an amplifier means connected to the same terminal B, an image inspection device 10 and a counter electrode means 100 arranged close to the pixel electrode connected to the TFT and forming a dummy pixel Cx between the pixel electrode. Then, the inspecting counter electrode means 100 is arranged on the drive substrate, and capacity is formed between with the pixel electrode by the counter electrode means 100. By detecting an electric change amount from the output signal read out from the capacity, the defective pixel of te drive substrate is detected. Thus, the pixel electrode of a liquid crystal display element is inspected even in the state without being sealed with the liquid crystal.