Abstract: An aluminum-halogen fuel cell has a positive electrode (2), a negative electrode (3), and an electrolyte (4) containing an ionic liquid represented by formula (1) or the like. In formula (1), R1 represents an unsubstituted or substituent-containing C1 to C20 alkyl group, R2 represents a C1 to C4 alkyl group or the like, each of R3 and R4 independently represents a hydrogen atom or the like, X represents AlCl4 or the like, and Y represents Al2Cl7 or the like.