Progress in the development of III-nitride materials has made possible the fabrication of many different types of electron devices. This chapter describes the main advantages of GaN-based electronics as well as some of the main electronic devices developed with this material system. We introduce the key material properties and figures of merit that make III-nitride materials ideal for many high-power/high-frequency applications. Then we focus on the different GaN diode structures developed so far, before discussing GaN bipolar transistors. Finally, we review the state of the art regarding field-effect transistors, both lateral and vertical.