Abstract: There is provided a flush type sprinkler head to be installed in the ceiling of a building, the sprinkler protruding out of the ceiling by a small distance. The sprinkler head comprises a main body defining a nozzle having a valve seat at the lower end, a cylindrical frame having a radially inwardly extending flange at the lower end, a valve member normally abutting against the valve seat to close the nozzle, a slidable deflector assembly fitting on the valve member and including a guide ring having slide bars extending downwardly from the guide ring and a deflector slidable along the slide bars, a coil spring interposed between the main body and guide ring and a break-up closure assembly adapted to break into pieces at rise in the temperature at the installation area of the sprinkler head and including a thermally responsive element.