A shielding device for surrounding and shielding an electronic element therein on a circuit board, comprising a unitary metallic frame for mounting on the circuit board defining a receiving space confronted with the circuit board; and a unitary metallic cover assembled with the frame so as to provide a complete shielding performance with the frame; wherein the cover pivots on the frame and moves between an opened state where the cover rotates away from the frame and a closed state where the cover is wholly covering on the frame.