n recent time GaN FETs have started its way on the electronics market. As the parameters of this type of semiconductors is superior to the classic Si and SiC elements the use of classic topologies like boost converter got the opportunity to set higher frequencies, better efficiency and therefore better power density. Better efficiency gives an advance in pay-off time as there is smaller amount of energy gets lost during conversion without introduction of “soft switching” techniques. The paper describes a design of Maximum Power Point Tracking (MPPT) converter power part prototype: modelling and experimental results. Voltage, current curves and efficiency of real prototype are compared to the results of simulations. The paper contains experimental results on prototype of boost MPPT converter. The efficiency vs. converted power curves is provided by power analyzer and compared to the theoretical ones estimated by modelling.