Thiamine monoglutamate (II) was readily obtained as a stable crystalline pentahydrate in a pure state by the ionic exchange reaction of thiamine monosulfate (I) with barium glutamate or thiamine monochloride (III) with silver glutamate in aqueous solution. II showed high solubility in water and had a taste just like as sodium glutamate. Moreover, it was found to be odorless and to give no bitter taste such as thiamine. Although the humidity affected the stability of powdered formulations of II with sodium chloride or sodium glutamate, II was found to be quite stable on storage for two months at 37℃ below 75% of humidity. The present results indicate that II will be practically utilizable for an enriched seasoning.