Abstract: A ground structure for a PECVD apparatus includes a ground connector is positioned in a receiving portion of a ground mount that is connected to an electrical reservoir. A cylindrical ground clamp holds the ground connector and includes an opening portion along a sidewall in a longitudinal direction. An outer surface of the ground connector makes contact with an inner surface of the ground clamp. A pair of stumbling portions are folded from an outer surface of the ground clamp and spaced apart from each other by a width of the opening portion. A ground wiring is connected to the ground clamp and the ground mount, and the ground current flows to the ground mount via the ground clamp by the ground wiring, thus the ground current is grounded to the electrical reservoir. Accordingly, the electric arc is prevented between the ground connector and the ground clamp.