Abstract: A secondary battery having a non-aqueous electrolyte according to the present invention includes a negative electrode using a carbonaceous material capable of doping and undoping lithium ions as the anode material, a positive electrode using a composite oxide of lithium and-a transition metal as the cathode material, and a non-aqueous electrolyte formed by dissolving an electrolyte into a non-aqueous solvent, the non-aqueous solvent containing methylethyl carbonate and dimethyl carbonate. According to the present invention, a secondary battery having a non-aqueous electrolyte in which normal charge/discharge reactions can be maintained even in battery overcharge and after high-temperature storage of the charged battery, and which exhibits high energy density, long cycle life, high safety performance and excellent environment-resistance, can be produced.