NOVELTY - A wound secondary battery has axial core (23) having long metal inner core component (37) and outer core component (39). Outer coat portion is formed of insulating material having heat conductivity of 1-20 W/mk. Insulated material is insulated resin material comprising inorganic filler having heat conductivity of 20 W/mk or more, and epoxy resin. Inorganic filler comprises metal oxide, metal nitride, metal carbide, metal hydroxide, ceramic powder and/or fiber. Content of inorganic filler is 10-100 volume parts with respect to 100 volume parts of insulated resin material.    USE - Wound secondary battery e.g. nonaqueous electrolyte secondary battery.    ADVANTAGE - The wound secondary battery is capable of sufficiently dissipating the heat generated in an electrode plate group to outside of battery at high temperature, while preventing dissipation of the heat at low temperature.    DETAILED DESCRIPTION - A wound secondary battery has electrode plate group (3) configured by winding a positive electrode plate and a negative electrode plate, which are interposed with separators, around an axial core having a long metal inner core component and an outer core component formed on the outer surface of inner core component. The outer coat portion in axial core is formed of insulating material having heat conductivity of 1-20 W/mk. The insulated material is insulated resin material comprising inorganic filler having heat conductivity of 20 W/mk or more, and epoxy resin. The inorganic filler comprises metal oxide, metal nitride, metal carbide, metal hydroxide, ceramic powder and/or fiber. The content of inorganic filler is 10-100 volume parts with respect to 100 volume parts of insulated resin material. The outer core component and inner core component have cylindrical shape. The cross-sectional area has shape which reduces, as the outer core portion goes to both ends from the center of longitudinal direction. The cross-sectional area has shape which increases, as the inner core portion goes to both ends from the center of longitudinal direction.    DESCRIPTION OF DRAWING(S) - The drawing shows a sectional view of nonaqueous electrolyte secondary battery.    Electrode plate group (3)    Negative electrode terminal (7)    Axial core (23)    Inner core component (37)    Outer core component (39)