A main object of the present disclosure is to provide a fluoride ion battery having a high charge-discharge potential. The present disclosure achieves the object by providing a fluoride ion battery comprising a cathode active material layer, an anode active material layer, and an electrolyte layer formed between the cathode active material layer and the anode active material layer, and the cathode active material layer includes a cathode active material having a composition represented by CuxS, wherein 1≤x≤2.