Abstract: A coin type battery having a structure that contributes to improved discharge capacity and prevent deposition of lithium metal is provided. A positive electrode plate (7) and a negative electrode plate (8) are folded at their connecting pieces and coiled around into a flat shape to construct an electrode plate group (1) such that layer faces of the positive electrode plate (7) and layer faces of the negative electrode plate (8) are alternately layered upon one another with a separator (9) interposed therebetween, and the electrode plate group is accommodated in a battery case made of a cap case (4) having an open end and a sealing case (5) for sealing this open end. An insulating member is provided to a connecting piece of the positive electrode plate (7) that is to be located at the center when the electrode plates are coiled around, on a face opposite one end of the negative electrode plate (8).