The invention provides a method capable of more simply and easily mass-producing sealed lithium secondary batteries having a stable battery performance. This method of manufacturing a sealed lithium secondary battery having an electrode assembly, an electrolyte solution and a sealable metallic or nonmetallic hard case of a given shape includes the steps of housing the electrode assembly, which includes a positive electrode and a negative electrode, and the electrolyte solution within the hard case; negatively pressurizing the interior of the hard case and sealing the hard case in the negatively pressurized state; carrying out, after the sealing step, initial charging so as to adjust the battery to a voltage at which the electrode assembly generates gases; and carrying out, after the initial charging step, main charging so as to charge the battery to a predetermined voltage. During the interval following the sealing step and up until the main charging step, the hard case is maintained in a sealed state so that the interior of the hard case is not open to the atmosphere.