A three-phase reactor includes: an outer peripheral iron core; and at least three iron-core coils that come in contact with an inner surface of the outer peripheral iron core or are joined to the inner surface. The at least three iron-core coils include corresponding iron cores and corresponding coils wound around the iron cores, and gaps that can magnetically connect one iron-core coil of the at least three iron-core coils and an iron-core coil adjacent to the one iron-core coil to each other are formed between the one iron-core coil of the at least three iron-core coils and the iron-core coil adjacent to the one iron-core coil.