Provided is an electrode assembly including: a negative electrode including a negative electrode current collector (NC) and a negative electrode active material layer (NAL) disposed on at least one surface of the NC; a positive electrode including a positive electrode current collector (PC), a positive electrode active material layer (PAL) disposed on at least one surface of the PC, and an undercoat layer being disposed between the PC and the PAL and being higher in resistance value than the PC. The negative electrode and the positive electrode are stacked on each other. In at least one side of the thus stacked negative and positive electrodes, the NAL projects from an edge of the PAL in a direction in which the NC and PC extend, and the undercoat layer projects from an edge of the NAL in the direction.