There is proposed a non-aqueous electrolyte secondary battery having an electrode assembly which is impregnated with a non-aqueous electrolyte solution, wherein the battery can be made thin while maintaining improved capacity, large-current characteristics and cycle life.The non-aqueous electrolyte secondary battery comprises a positive electrode, a negative electrode, a separator and a non-aqueous electrolyte solution. The production process of the battery comprises steps of preparing an electrode assembly by interposing a separator between a positive electrode and a negative electrode, impregnating the electrode assembly with an organic solvent which can dissolve the binder of the positive- and/or negative electrodes, bonding the positive electrode and the separator together and bonding the negative electrode and the separator together by drying the electrode assembly, and impregnating the electrode assembly with a non-aqueous electrolyte solution.