A gate drive device for driving a plurality of semiconductor devices connected in parallel to each other includes a constant current circuit, a plurality of switching element, and a drive controller. The constant current circuit supplies a constant current to respective gates of the plurality of semiconductor devices. The plurality of switching elements is respectively provided on a plurality of paths that connects the constant current circuit and the respective gates of the plurality of semiconductor devices. The drive controller controls driving of the plurality of switching elements to supply the constant current from the constant current circuit to the respective gates of the plurality of semiconductor devices.