The Idojiri Museum of Archeology that is located at the foot of Yatsugatake Mountains in Nagano, Japan is well known worldwide for their excellent collections of Jomon Potteries of about 5,000 years B.P. This illustrated booklet is published as the 1st volume of Idojiri Collections Series and it contains 10 masterpieces of Jomon potteries that are uncovered at the dwelling site #32 of Tounai Ruins including the comments on the ruins and each artifact based on the latest report of the excavation.