Disclosed are a power semiconductor device and a method of fabricating the same which can increase a breakdown voltage of the device through a field plate formed between a gate electrode and a drain electrode and achieve an easier manufacturing process at the same time. The power semiconductor device according to an exemplary embodiment of the present disclosure includes a source electrode and a drain electrode formed on a substrate; a dielectric layer formed between the source electrode and the drain electrode to have a lower height than heights of the two electrodes and including an etched part exposing the substrate; a gate electrode formed on the etched part; a field plate formed on the dielectric layer between the gate electrode and the drain electrode; and a metal configured to connect the field plate and the source electrode.