An oxygen measurement device (10A) is provided with: a urethral catheter (18a)； and an oxygen sensor (20a) which has an oxygen sensor body (50a) capable of detecting oxygen in urine. A shaft (22a) is provided with a urine introduction hole (28a) into which urine in a bladder (140) is allowed to flow, and with a urinary tract (74) which is communicatively connected to the urine introduction hole (28a) and through which urine flows. The oxygen sensor (20a) is provided to the urethral catheter (18a) such that the oxygen sensor body (50a) comes into contact with urine flowing in the urinary tract (74).
