It is an object of the present invention to provide a processing apparatus which is capable of performing uniform dispersion, dissolution, solubilization, emulsification of gas into liquid, and uniform dispersion, dissolution, solubilization, and emulsification of liquid to heterogeneous liquid by a large capacity and in a short time.The invention includes a pressurizing centrifugal pump 1, a circulating portion 25 configured to circulate gas/liquid or liquid/liquid fluid from a feed port 6 to an intake port 3 of the pressurizing centrifugal pump 1, a nozzle portion 30 provided on the downstream of the pressurizing centrifugal pump 1 in the circulating portion 25 and having a minute opening configured to allow passage of the fluid pressurized by the pressurizing centrifugal pump 1, and a chamber 50 provided on the downstream of the nozzle portion 30 in the circulating portion 25 and provided with the chamber 50 which can store the fluid.
