A method of detecting a position of a mark within image data. The method includes a first step of obtaining a first position of the mark based on a first degree of correlation between a first template and the image data, the first template having a first feature point to obtain the first degree of correlation, a second step of obtaining a second position of the mark based on a second degree of correlation between a second template and the image data, the second template having a second feature point, of which a position is different from that of the first feature point, to obtain the second degree of correlation, and a third step of detecting the position of the mark through the first and second steps.