A method for automatically inspecting positive and negative polar directions of a polar element on a substrate is provided. Firstly, an image of a standard substrate is retrieved to form a standard sample, and relevant data of the polar elements on a substrate to be inspected is obtained to form the inspected sample. Then, transforming the geometry coordinates to the pixel coordinates, using different shapes of frames to make each polar element be positioned within, and marking the positions, positive and negative polar directions of all the polar elements in the image of the standard substrate. A database is set up to record the relevant data of each polar element as the standard sample for inspecting. The standard sample is compared with all the samples to be inspected to inspect whether the polar directions of each polar element is correct or not.