PURPOSE: To provide a pregelatinized starchy processed food in a solid form, hardly again even in preservation under chilled conditions and preservable for a long period by applying amylase to the surface of a pregelatinized massive potato or noodles or pastas in a wet state.

CONSTITUTION: A pregelatinized massive potato or noodles or pastas in a wet state are produced by a method for steaming or boiling the whole peeled potato, dicing the potato, quickly cooling the diced potato or boiling wheat vermicelli, macaronis, etc., draining and cooling the boiled wheat vermicelli, macaronis, etc. The resultant pregelatinized food in the wet state is then mixed with amylase and, as necessary, a seasoning, etc., to apply the amylase to the surface of the food and produce the objective solid hardly retrograding pregelatinized starchy processed food. Furthermore, β-amylase and glucoamylase are preferred as the amylase. α-Amylase tends to provide the sticky final product and deteriorate the texture.