4-panel of Im height and 45cm width were fixed on the 40cmx40cm bottom plate and the opening of the panel comer was 5cm. Diameter of stainless vessel is 10em and its height is 2cm and it located at the center of the bottom plate. 78mL liquid fuel was filled in the vessel and its depth was lcm. Flame temperature was measured with K type thermocouple, and radiation heat of flame was measured with heat flux meter. Flame height and its behavior was visualized with video camera. and mass burning rate was measured by fuel combustion time. According to the development of fire, flame swirling was begin. From the experiment the mass burning rate was larger and the height of flame was higher than the usual pool fire flame. Flame temperature and heat flux also increased far more than the pool fire. Consequently the swirling air flow through the openings between the panel and thermal buoyance contribute to increase of heat release rate, flame length and mass burning rate.