PURPOSE: To provide an apparatus which can accelerate hydrolysis in a hydrolytic apparatus for regenerating material strength without deteriorating same.

CONSTITUTION: A rotary shaft 13d equipped with a screw vane 13e is provided in a cylindrical casing 13c having a pulverized material-supplying opening 13f, a pulverized material-discharging opening 13g, a steam-supplying opening 13h, and a steam-discharging opening 13j. The rotary shaft is hollow and constructs a passage for steam. The steam is jetted from a steam-jetting opening provided around the rotary shaft, and keeps an atmosphere in a hydrolytic chamber at a temperature wherein synthetic resin is not melted. Further, only a paint film is raised in temperature by irradiation of a microwave from microwave generators 13z1...13zn, and the paint film can be more quickly hydrolyzed and made low molecular weighted. Therefore, material strength of a part produced from the pulverized material comes to be strength equal to that produced from a new material.