To provide a clinical thermometer which can be taken out with a hook, etc., easily even if it is accidentally dropped into an organ.

A clinical thermometer 1 is made of glass, provided with a cylindrical main body case 2 whose cross section is elliptical. Relating to the main body case 2, a temperature-sensitive part 3 comprising a mercury reservoir is formed at its one end, while the temperature-sensitive part 3 is connected to a glass capillary 4. The glass capillary 4 is provided with a temperature indication plate 5. Near the other end part 2e of the main body case 2, an hooking through hole 7 is provided. The hooking through hole 7 is opened at an rear protruding part 6 extending backward integral with the main body case 2. The hooking through hole 7 is formed to such size as a hook, a cord, etc., can be inserted.