PURPOSE: To afford promix fibers containing acrylic fibers and a protein such as milk casein with soft touch feeling.

CONSTITUTION: A promix textile fabric is subjected to wash processing under enzymatic treatment in a rotary drum washer filled with a protease-contg. aqueous solution, physical action is applied to the textile fabric by making use of fluid flow owing to the rotary drum revolution to bring the fabric to such a state as to easily decompose the protein therein, thus decomposing the protein with the protease. And during the rotary wash processing, the textile fabric is held with a separator and prevented from developing wrinkles and foldings.