Abstract: A method of manufacturing single-crystal diamond particles, according to the present invention, comprises the steps of introducing a reaction gas containing at least one organic compound into a reaction vessel having an anode and a cathode, producing a plasma by DC discharge caused between the anode and the cathode, and vibrating inorganic single-crystal particles in the plasma and depositing single-crystal diamond on the surface of the single-crystal particles. According to the method of the present invention, single-crystal diamond particles can be manufactured at high growth rate and with excellent reproducibility.

Abstract: A capacitance humidity sensor according to the disclosure a non-conductive base plate, electrodes oppositely arranged on the base plate, a metal compound membrane formed by ion-plating independently on the electrodes, the metal compound membrane being roughened on its surface by plasma etching and being active to the humidity, and a moisture permeable metal skin formed on the metal compound membrane. The metal compound is preferably an oxide or nitride of aluminum or magnesium.