An electric heater includes a substrate, an outer pattern part disposed on one surface of the substrate, an inner pattern part disposed on the one surface of the substrate so as to be located such that the outer pattern part surrounds the inner pattern part, and to be spaced apart from the outer pattern part. A pair of first electrodes is connected to the outer pattern part and a pair of second electrodes is connected to the inner pattern part and spaced apart from the pair of first electrodes, and the pair of second electrodes are located inside the outer pattern part.