Teaching apparatus and substrate alignment apparatus using the same

A teaching apparatus includes a chamber; an electrostatic chuck in the chamber, the electrostatic chuck including a sidewall surrounding a loading area; an aligner configured to be loaded onto the loading area of the electrostatic chuck; a vision sensor configured to obtain measurement data by measuring separation distances of separation regions between the aligner and the sidewall of the electrostatic chuck and to transmit the measurement data; a transfer robot configured to load the aligner onto a reference position of the loading area and to position the vision sensor above the electrostatic chuck; and controller configured to reset the reference position and to equalize the separation distances based on the measurement data transmitted from the vision sensor.