The present invention provides a seaweed that has visual, gustatory, and other attributes as a seaweed, can be enjoyed as a seaweed food product, and is softened to the extent of being crushable merely with the tongue in the mouth, and provides a method for producing said seaweed. Provided is a production method that comprises a step for bringing seaweed into contact with an aqueous solution containing a phosphate and/or an organic acid salt. A seaweed that has visual, gustatory, and other attributes as a seaweed, can be enjoyed as a seaweed food product, and is softened to the extent of being crushable merely with the tongue in the mouth is provided by this production method.
