A finger-clipped oximeter includes an upper case (2) in which a measuring element (4), a data processing circuit, batteries (6) and a display (3) are provided, a rectangular through hole being provided in the upper case (2); a finger pressed plate (10) in which a measuring element is also provided, a finger inserting hole (11), a rectangular column (7) with a position corresponding to that of the rectangular through hole of the upper case (2); and a pair of connectors which are capable of ascending or descending, each of the connectors including one U-shaped connecting rod (8).