A robust controller for a single-phase PWM inverter is designed. The single-phase PWM inverter generates an AC sinusoidal output from a link DC voltage. The important points in this inverter are both the robustness of the output waveform against load variations and minimum Total Harmonic Distortions. The main problem with this method results from the changes in the inverter’s transfer function by load variations, So it is necessary to use a robust controller such as H-infinity. The simulation’s results show robustness of this controller against dynamic loads variations.