A present invention provides a lithium ion storage device capable of reliably doping a negative active material of a negative plate (19) with lithium ions generated through dissolution of a lithium metal plate (31) disposed in an electrode group (11). A conductive shielding member (33) includes a current collecting metal foil (35) and a negative active material layer (37) formed on at least one surface of the current collecting metal foil (35). The conductive shielding member (33) is provided between a lithium metal plate (31) and a positive plate (17) such that the lithium metal plate (31) is sandwiched between the negative plate (19) and the negative active material layer (37) formed on the current collecting metal foil (35) of the conductive shielding member (33).
