A substrate treatment apparatus is provided, which includes: a seal chamber including a chamber body having an opening, a lid member provided rotatably with respect to the chamber body and configured to close the opening, and a first liquid seal structure which liquid-seals between the lid member and the chamber body, the seal chamber having an internal space sealed from outside; a lid member rotating unit which rotates the lid member; a substrate holding/rotating unit which holds and rotates a substrate in the internal space of the seal chamber; and a treatment liquid supplying unit which supplies a treatment liquid to the substrate rotated by the substrate holding/rotating unit.