Soba may be broken down by buckwheat flour producing area, region, and country whereby, in that case, buckwheat flour is identified as a product of Shinshu Kaiden Kogen, Hokkaido, North America, China and the like.
信州開田高原産・北海道産・北米産・中国産など、蕎麦粉の産地・地方・国の違い等で区分。