A spot detecting apparatus includes a photographing part and a spot detecting part. The photographing part photographs, in a first resolution, an image displayed on a display panel to output first resolution image data, and photograph, in a second resolution, the image displayed on the display panel to output second resolution image data, where the second resolution is higher than the first resolution, and the image displayed on the display panel includes a first spot greater than or equal to a reference size and a second spot less than the reference size. The spot detecting part receives the first resolution image data and the second resolution image data, and subtracts the first resolution image data from the second resolution image data to detect the second spot.