A load port includes: a base; a mounter mounting thereon a container accommodating substrates; a scanner detecting the substrates; and a determiner making a determination regarding a state of each substrate detected by the scanner, wherein the scanner detects first to third portions of an end surface of each substrate, while a fixed state, in which the container is mounted on the mounter and an angle of the container about a vertical axis with respect to the base is fixed, is maintained, and wherein the determiner determines whether each substrate is normally accommodated in the container by using information on a first position and information on a second position, and calculate an amount of vertical deflection of a substrate normally accommodated in the container by using the information on the first position, the information on the second position, or both, and information on a third position.