An exposure device includes a determining unit determines specific transfer patterns, which are transfer patterns of predetermined portions of a unit pattern, among transfer patterns projected through a photomask including an internal pattern having a plurality of unit patterns that is arranged at a predetermined interval and has the same shape, for two or more unit patterns, an error calculating unit calculates an error between the transfer pattern and the specified transfer pattern on the basis of the comparison between the relative position between the specific transfer patterns and a specified value of it, a correction parameter calculating unit calculates correction parameters for correcting the transfer patterns on the basis of the calculated error, and a correction control unit corrects exposure conditions using the correction parameters such that the transfer patterns are corrected.