According to an aspect of the present invention, in a case where a part of the plurality of head modules to each of which an initial amount of correction is set is replaced, a mounting position of the replaced head module in the first direction varies in a range within the mounting tolerance. However, the initial amount of correction in the first direction of each of the head modules is set by adding the amount of the offset more than the mounting tolerance, a mounting position of the replaced head module is always upstream from the offset reference line in the feeding direction of a recording medium. Thus, it is required to correct only an amount of correction of the replaced head module with reference to the offset reference line, so that the amount of correction of a non-replaced head module can be used without being corrected.