The objective of this investigation was to determine the effects of mineral contents, hardness and color of the ash-treated and untreated Wakame thalls during storage at 20℃ condition. On the other hand, mineral contents and hardness of dipped specimens in water were evaluated, and also, the influences of mineral contents in cooked specimens were estimated from viewpoint of cooking. The obtained results were as follows; 1) Although mineral contents of untreated specimens did not markedly change during 70 days storage, calcium and iron contents of ash-treated specimens were remarkably increased after 30 days storage. The hardness of ash-treated specimens was higher than that of untreated ones, but the both of them was gradually decreased after 30 days storage, and the fresh color of ashtreated specimens was maintained in comparison with untreated ones. 2) All mineral elements in specimens were more or less decreasd by dipping treatment in water, and especially, potassium, natrium, calcium and iron in specimens were more eluted after dipping treatment for 5 to 10 minutes. Bisides, the hardness of the both of ash-treated and untreated specimens was gradually decreased according as long of dipping time, but the hardness of asn-treated specimens was exceeded in comparison with untreated ones. 3) All mineral elements in specimens were more or less decreased by treatments of dipping in vinegar, boiling and dipping in hot water, and especially, calcium and magnesium contents in specimens were remarkably decreased by dipping treatment in vinegar