A semiconductor device (200) is provided, including a substrate (210), and an active circuit (220) and a dummy circuit (230) that are mutually insulated. The dummy circuit (230) includes a lightly-doped P base (231) disposed in the substrate (210), a heavily-doped dummy source drain region (232) disposed in the P base (231), a dummy metal layer (235) disposed on a surface of the substrate (210), and a metal column (233) connecting the dummy source drain region (232) and the dummy metal layer (235). The heavily-doped dummy source drain region (232) and the lightly-doped P base (231) form non-directional low-impedance resistance, so that charges accumulated on a metal conductor rapidly transfer in a direction perpendicular to the substrate (210). This reduces damage caused by the charges to a circuit, and improves reliability and a yield rate of a chip.