Disclosed is a stator assembly, which includes a stator core having a circular base part, a plurality of teeth radially formed on an outer face of the base part, and a tooth end portion at the end of the teeth, the stator core comprising a first coating layer formed on an entire surface of the base part and the teeth; and a second coating layer formed on a surface of the first coating layer, wherein the entire surface of the base part and the teeth is coated with the first coating layer and the entire surface coated with the first coating layer is coated with the second coating layer, and wherein the first coating layer and the second coating layer are made of insulating powder.