According to the present invention, there is provided a plasma polymerization surface modification of a metal for enhancing its applicability for use in refrigerating and air conditioning such as in constructing heat exchanges, by using a DC discharge plasma, comprising the steps of: (a) positioning an anode electrode which is substantially of metal to be surface-modified and a cathode electrode in a chamber, (b) maintaining a pressure in the chamber at a predetermined vacuum level, (c) blowing a reaction gas composed of an unsaturated aliphatic hydrocarbon monomer gas or fluorine-containing monomer and silicon containing monomer gas at a predetermined pressure and a non-polymerizable gas at a predetermined pressure into the chamber, and (d) applying a voltage to the electrodes in order to obtain a DC discharge, whereby to obtain a plasma consisting of positive and negative ions and radicals generated from the unsaturated aliphatic hydrocarbon monomer gas and the non-polymerizable gas, and then forming a polymer with hydrophilicity or hydrophobicity on the surface of the anode electrode by plasma deposition, and there is also provided a plasma polymerization surface modification of a metal for enhancing its applicability for use in refrigerating and air conditioning such as in constructing heat exchanges, by using an RF plasma.