Provided are a method for producing highly nutritious, softened plant material that retains the form of the plant material, and softened plant material obtained using said production method. The highly nutritious, softened plant material that retains the form of the plant material is produced by introducing catabolic enzymes so that when the catabolic enzyme is introduced, the plant material and catabolic enzyme are brought into contact and reduced pressure treatment is performed multiple times so that the total time under reduced pressure is less than 12 minutes.