Integrated bilateral switch power device based on gallium nitride, including a die integrating a first and a second switch FET transistor, and a substrate-biasing network configured to electrically couple the substrate node selectively to the source region of the first and the second switch FET transistors which is at a lower potential. The substrate-biasing network has a first and second diode coupled in anti-series and formed by field effect, diode-connected transistors having the same structure as the first and the second switch FET transistors in the same conduction, contact and gate layers.