The present invention provides an insulated wire having a conductor and at least two insulating coating layers formed surrounding the conductor, wherein the insulating coating layers comprises the outermost layer thereof, which has a thickness in the range of 20 to 50% based on the total thickness of the insulating coating layers and comprises a polyimide resin; and a base insulating coating layer in contact with the conductor, which has a thickness in a range of 50 to 80% based on the total thickness of the insulating coating layers and comprises a polyamide-imide resin having an adhesion-improving agent. The insulated wire of the present invention has insulating coating layers having superior coating adhesion as well as good heat-resistance.