In this thesis work we constructed a measurement circuit for measurement of the inductor current in the buck converter BMR450. We theoretically show that the voltage across the capacitor is directly proportional to the inductor current in the BMR450. We designed a test bed to enable the measurement of the inductor current. On the base of the measurement signal we derived the average inductor current for different resistive loads. We draw schematic PCB layout for the measurement circuit. During the project we observed that the measurement electronics has to be chosen for relatively high bandwidth, about 2MHz. We also observed that the measurement signal has a large noise magnitude, induced by the transistor switchings. The noise magnitude directly after the switching is so high that the part of the measurement signal was not used in the further calculations.