Provided are a beam scanning device and a system including the beam scanning device. The beam scanning device includes: a spatial light modulator configured to modulate a phase of a light for a corresponding pixel of a plurality of pixels; and a phase mask including a support plate arranged in an output direction of the light that is output from the spatial light modulator and a plurality of nanostructures arranged on the support plate differently for each of the plurality of pixels to control the phase of the light.