Process for surface treating molded articles of fluorine resins

A process for surface treating a molded article, which comprises subjecting a molded article of a fluorinated olefin polymer to sputter etching by bringing the fluorinated olefin polymer into contact with a cathode in a chamber internally equipped with an anode and the cathode with the minimum distance between the anode and the cathode being substantially 1/.sqroot.P, wherein P is the pressure in Torr, said chamber being capable of being evacuated to provide a vacuum therein, and in this state applying a high frequency of several hundred KHz to several ten MHz alternating current between the anode and the cathode while maintaining the pressure and temperature of the gaseous atmosphere in the chamber at about 0.0005 to about 0.5 Torr and about -10.degree. C to about 40.degree. C, with the product of the discharge power for the sputter etching and the treating time being about 1 to about 1,000 watt. sec/cm.sup.2, to thereby sputter etch the molded article in the resulting cathode dark space.