An apparatus for judging cell detachment that judges a state of detachment of cells that have been cultured within a cell culture container (cultured cells), includes: an image-capturing unit that captures an image of the cultured cells; and a detachment state judging unit that determines luminance information within the cell culture container based upon image capture data from the image-capturing unit, and judges that the culture cells are detached when the luminance information exceeds a predetermined luminance level.