Two-dimensional (2D) materials such as WSe 2 are potential for advanced electronics because of their ultra-thin geometry and unique electrical properties. Herein, a simplified high-performance WSe 2 complementary inverter based on a buried gate is demonstrated on an individual ambipolar WSe 2 flake, in which both n- and p-type WSe 2 transistors are achieved by local doping. The n-type doping is induced by the donors of benzyl viologen, showing an electron mobility of 28.1 cm 2 /V.s. In contrast, the p-type one is realized by Ozone exposure with a high mobility of 36.8 cm 2 /V.s. The buried gate enables enhanced electrostatic coupling, with a supply voltage (V dd ) of 5 V, and the complementary inverter demonstrates a voltage gain beyond 32, almost ideal noise margin approaching 0.5V dd and low static power consumption. This work paves the way to achieve high-performance 2D material complementary inverters with simplified fabrication process.