A cerebral-ischemia supervisory monitor includes: a pair of optical fibers which each have a tip part that can be placed substantially perpendicularly to an exterior surface of a cerebrum; an irradiation portion which is connected to a basic end part of one of the optical fibers, and via this optical fiber, can irradiate the exterior surface of a cerebrum with ultraviolet rays; a light-receiving portion which is connected to the basic end part of the other one of the optical fibers, and via this optical fiber, can receive fluorescence that is emitted when the ultraviolet rays excite cerebral cells; and a display portion which can display an intensity of the fluorescence.