A phase control device (100) includes a two-dimensional array of three-dimensional units (10) and is configured to control a phase of an electromagnetic wave passing through the three-dimensional units (10). Each three-dimensional unit (10) includes a substrate (12) and an active control layer (11). The active control layer (11) includes metal patches (111) and (112), and a modulator (113) disposed between the two metal patches and connected to each of the two metal patches. The substrate (12) includes at least one bias line (114 or 116) connected to one of the two metal patches and extending in a direction perpendicular to a direction of an electric field of the electromagnetic wave.