An oxygen measurement device includes a catheter including a flexible hollow shaft, the flexible shaft having an open port configured to allow urine from a bladder to flow into the open port, and a urinary passage in communication with the open port configured to discharge the urine; and an oxygen sensor including an oxygen sensor main body capable of detecting oxygen in the urine, the oxygen sensor being disposed in the catheter and configured such that the oxygen sensor main body is in contact with the urine flowing in the urinary passage.