A BOILER

PURPOSE: A boiler is provided to increase the efficiency of hot water by smoothly circulating water on the bottom surface by loading a high temperature water in the upper part of the lower temperature. CONSTITUTION: A boiler comprises a body unit(10), a first tank(12), a second tank(14), opening and closing unit(18), an inlet path(20), a dispersing unit(22), an outlet(24), and a heater(26). The inlet path penetrates through the first tank and the second tank by vertically penetrating through the upper surface of the body unit and is connected to the bottom surface by penetrating through the opening and closing unit. The dispersing unit is protruded to the inlet path on the bottom surface contacting to the inlet path. The outlet is formed in order for the water to be discharged to the outside on one end of the first tank.