Abstract: Provided is a substrate treatment device. The device includes: a substrate support member supporting a substrate to be treated; a rotation driving member rotating the substrate support member; a container provided around the substrate support member; and a treatment solution supply unit including a photoresist nozzle for supplying a photoresist to a top surface of the substrate, wherein the photoresist nozzle starts supplying the photoresist while the substrate support member rotates at a first supply speed and stops supplying the photoresist while the substrate support member rotates at a second supply speed decelerated from the first supply speed.