A lithium-ion secondary battery having stable charge characteristics and lifetime characteristics is manufactured. Before the secondary battery is completed, a positive electrode is subjected to an electrochemical reaction in a large amount of electrolyte solution in advance, so that the positive electrode can have stability. The use of the positive electrode enables the secondary battery to be highly reliable. If a negative electrode is also subjected to an electrochemical reaction in a large amount of electrolyte solution in advance, the secondary battery can be more highly reliable.