Abstract: A fire extinguisher selectively operable either manually or automatically is disclosed. The fire extinguisher comprises a container (100), a body (200), a discharge nozzle (600), an operating rod assembly (300), and an operating lever (400). The container (100) contains an extinguishing medium (110) under a pressure. The body (200) is fitted to the upper end of the container (100) and has a passage for releasing the extinguishing medium (110) under a predetermined condition. The discharge nozzle (600) is fitted to one portion of the body (200) to communicate with the passage and discharges the extinguishing medium (110). The operating rod assembly (300) manually controls an opening of the passage by applying a predetermined external force or automatically controls an opening of the passage under a predetermined temperature condition e operating lever (400) is located at the other portion of the body (200) and applies the predetermined external force to the operating rod assembly (300).