A medium conveying apparatus conveyable a passport includes a guide pair including a first guide, and a second guide located so as to sandwich a medium conveyance path together with the first guide, to regulate a vertical direction of the medium conveyance path, a light emitting element located on an outside of the medium conveyance path with one of the first guide or the second guide in between to detect the medium, a light receiving element located on an outside of the medium conveyance path with the first guide in between, to receive a light emitted by the light emitting element, and an opening provided in the first guide, to pass the light emitted from the light emitting element. A reflectivity in a periphery of the opening of the first guide is 55% or less.