The present disclosure relates to a substrate unit of a nanostructure assembly type, an optical image apparatus including the same, and a controlling method thereof, and the substrate unit of the nanostructure assembly type according to an exemplary embodiment includes: a lower substrate; an upper substrate separated from the lower substrate, an observation object being able to be positioned at the upper substrate; and at least one metal nanostructure positioned on the lower substrate, wherein the at least one metal nanostructure is capable of being assembled on the lower substrate or separated from the lower substrate.