This article discusses a design procedure of DC-AC inverter. The DC-AC inverter is to produce a sinusoidal AC voltage with adjustable amplitude and frequency. Pulse-width modulation (abbr. PWM) is one of the most used techniques in static inverters. For the PWM, the switching angle is most important, and the switching angle controls the efficiency of DC-AC inversion. For this reason, the design of the optimal switching angle vector is very important. In this article. we obtain such switching angle vector by particle swarm optimization system (abbr. PSO). Our simulation results indicate that the proposed design procedure gives high efficiency inversion.