PURPOSE: To obtain the title soy sauce of low common salt content, excellent in healthiness because of containing minerals, requiring only a small amount of broth, with no need for any chemical seasoning, by admixing soy sauce with an appropriate amount of seawater.

CONSTITUTION: Seawater is put to sterile filtration, and an appropriate amount thereof is added to soy sauce followed by agitation, thus obtaining the objective soy sauce. For example, such seawater put to sterile filtration is mixed with the same amount of soy sauce. Thereby, natural intake of the useful minerals and trace ingredients in seawater and enjoyment of the mellow taste of the present soy sauce will get ensured. Furthermore, concern for sodium overintake can be eliminated.