A metal separator molding device is provided for molding a metal separator by press-molding a thin plate-shaped base material by using a first die and a second die capable of moving towards and away from each other. The metal separator molding device has a first heating part for heating the thin plate-shaped base material, a channel-processing part for pressing the thin plate-shaped base material heated by the first heating part using the first die and the second die to form channels through which a medium flows, and a controller for controlling the operations of the first heating part and the channel-processing part.