TWI803755B

This substrate treatment device includes: an opposing member that has a disk part having an opposing surface opposing, from above, a substrate held by a substrate holding unit and an extension part extending from the disk part to the outside in the radial direction centered on a vertical axis; an annular member that encircles the substrate held by the substrate holding unit in a plan view; and an opposing member lifting and lowering unit for lifting and lowering, in cooperation with the annular member, the opposing member such that a blocked space to which the inflow of atmosphere from the outside is restricted is demarcated by the substrate, the opposing member, and the annular member. The annular member has a guiding surface for, when a substrate rotation unit rotates the substrate held by the substrate holding unit, guiding a treatment liquid present on the upper surface of the substrate, by centrifugal force, radially outward relative to a circumferential edge section of the substrate. The extension part