To provide the constitution of a lithium ion secondary battery making a distinction of polarity between a positive electrode and a negative electrode unnecessary.

A lithium ion secondary battery 1 includes a lithium ion secondary battery base body 10 including a first electrode 11, a second electrode 12 and a solid electrolyte 13; and a housing member 20 housing the lithium ion secondary battery base body 10. Each active material of the first electrode and the second electrode of the lithium ion secondary battery base body 10 contains Li2FeS2. The housing member 20 includes an insulating substrate 21 having a surface on which the lithium ion secondary battery base body 10 is placed and a metallic cover member 22 joined with the insulating substrate 21 so as to cover the lithium ion secondary battery base body 10 placed on the surface of the insulating substrate 21. An insulator 30 is arranged in the inner space of the housing member 20 so as to surround the lithium ion secondary battery base body 10.