Provided is a high electron mobility transistor including: a channel layer comprising a 2-dimensional electron gas (2DEG); a barrier layer on the channel layer and comprising first regions and a second region, the first regions configured to induce the 2DEG of a first density in portions of the channel layer and the second region configured to induce the 2DEG of a second density different from the first density in other portions of the channel layer; source and drain electrodes on the barrier layer; a depletion formation layer formed on the barrier layer between the source and drain electrodes to form a depletion region in the 2DEG; and a gate electrode on the barrier layer. The first regions may include a first edge region and a second edge region corresponding to both ends of a surface of the gate electrode facing the channel layer.