This paper examines the hard flat stones called Teppeiseki as the roofing material in Suwa district. The stones began to be used on roof in the Edo era to press roofing boards. The roof with boards and the stones varied during the Meiji era and finally changed into the roof with the stones and no boards. Above all the roofing made only of the diamond-shaped Teppeiseki stones prevailed for its good rainproof. The Teppeiseki stones started to cover the roofs of storehouses for cocoon in the 1890's and then spread to houses in the first quarter of the twenty century.
