A surface treatment device includes at least one paddle in a plate shape, in a surface treatment tank, for stirring a surface treatment solution near a substrate by reciprocally moving the paddle with respect to the substrate. The paddle is configured by integrally forming multiple square bars provided in a depth direction or a horizontal direction of the surface treatment solution at regular intervals along the substrate. A liquid draining member for draining a liquid is arranged in at least one side of an end of the paddle.