In this paper fractional order proportional integral derivative (FOPID) controller tuned with genetic algorithm (GA) is used to control of a novel designed sinusoidal output inverter. FOPID is used to minimize the total harmonic distortion (THD), increase efficiency and output voltage in order to obtain sinusoidal wave form. In this topology fully rectified form of a sinusoidal voltage waveform at a utility amplitude and frequency is achieved by a well-known buck-boost converter which has been converted to AC voltage. A conventional well-tuned PI controller is already applied to inverter in the previous paper [1]. The comparison of the FOPID and the PI is presented by taking into consideration their low THD, high efficiency and high output voltage at the inverter output under the same conditions. The simulation results prove that the FOPID shows better performance than the PI controller in terms of efficiency, THD level and output voltage.