A main object of the present application is to provide a battery including an insulating member that insulates a battery case from an electrode body and is able to secure good injection performance of an electrolyte solution. The battery provided by the present application includes an electrode body provided with a positive electrode and a negative electrode, and a battery case that houses the electrode body together with an electrolyte solution. An insulating member that isolates the electrode body from the battery case is arranged between the electrode body and the battery case, and the insulating member is formed into a bag shape that encloses the electrode body and is made of a porous material having pores through which the electrolyte solution is able to flow.