To artificially create hot water by the magnetic fields formed by the hot water of Manza Hot Spring of Gunma Prefecture, the magnetic fields formed by the hot water of Kakeyu Hot Spring of Shinshu or the magnetic fields formed by the hot water of Yamada Hot Spring of Shinshu and the hot water of natural hot springs different therefrom

The hot water is brought into contact with the N pole faces of the andesite and the S pole faces of the andesite in order to create the same magnetic fields as the magnetic fields of the hot water of Manza Hot Spring and the hot water is brought into contact only with the N pole faces of the andesite in order to create the same magnetic fields as the magnetic fields of the hot water of Kakeyu Hot Spring or the hot water is brought into contact only with the S pole faces of the andesite in order to create the same magnetic fields as the magnetic fields of the hot water of Yamada Hot Spring.