A plasma generator according to an embodiment of the present invention is provided to generate a high density and stable plasma at near atmospheric pressure by preventing a transition of plasma to arc. The plasma generator includes a plate-shaped lower electrode for seating a substrate; and a cylindrical rotating electrode on the plate-shaped lower electrode, wherein the cylindrical rotating electrode includes an electrically conductive body that is connected to a power supply and includes a plurality of capillary units on an outer circumferential surface of the electrically conductive body; and an insulation shield layer that is made of an insulation material or a dielectric material, exposes a lower surface of the plurality of capillary units, and shields other parts.