An enzyme treatment solution of the present invention is adapted to be used in a softening method for softening an animal-based food material composed of meat or fish and shellfish by subjecting it to an enzyme treatment using the enzyme treatment solution. pH of the enzyme treatment solution is 8.0 or higher but lower than 10.5, and a salimeter measurement value obtained by measuring an electrolyte concentration of the enzyme treatment solution using a salimeter as a salt concentration is 0.7% or more but less than 3.0%. This makes it possible to reliably soften the animal-based food material while maintaining mouthfeel and flavor thereof, thereby obtaining a softened animal-based food material having smooth mouthfeel.
