The utility model relates to an electric heater. The electric heater comprises an outer shell box body, a rear plate of the outer shell box body is provided with an air inlet, and a fan is arranged on the inner side of the rear plate. A heating device is mounted in the box body, the heating device is electrically connected with a circuit control assembly, and the heating device comprises a heating plate and a fluid flow channel plate. The heating plate comprises a metal base body, and one side of the metal base body is covered with an electric heating film layer. The fluid flow channel plate and the heating plate are fixedly connected in a sealing mode to be combined into a heating device tube cavity, a water inlet and a water outlet of the heating device tube cavity are respectively provided with an overflow valve, and circulating water pumps are further arranged in the heating device tube cavity. According to the electric heater, the electric heating film layer is used in the heating device for heating, heating is quick, due to the fact that the water inlet and the water outlet of the heating device tube cavity are respectively provided with one overflow valve, it is guaranteed that the water inlet and outlet backflow phenomenon of the heating device can be avoided, through the circulating water pumps arranged in the heating device tube cavity, it is guaranteed that hot water in the heating device can be circulated normally, when heat produced by the heating device is blown out by the fan, the blown heat is even, and the local air warming phenomenon can be avoided.