1. A target setting apparatus that sets a target correcting a sight line detection portion to detect a sight line of a subject person, a deviation between a position of the target and a position detected as a center of the sight line detected by the sight line detection portion when the subject person is estimated to be gazing at the target being regarded as a detection error of the sight line detection portion and being applied to a correction, the target setting apparatus comprising: a sight line range estimation portion that estimates a sight line range within which the sight line of the subject person moves; a candidate point extraction portion that extracts a candidate point (Tc) for the target from the sight line range, which is estimated by the sight line range estimation portion; a candidate point evaluation portion that evaluates appropriateness of the candidate point as the target by using a plurality of indices, the candidate point being extracted by the candidate point extraction portion; and a target setting portion that determines, based on the appropriateness evaluated by the candidate point evaluation portion as the target, whether or not to set the candidate point as the target.