A substrate treatment apparatus includes: a substrate holding unit which horizontally holds a substrate; a liquid droplet nozzle which generates droplets of a treatment liquid which are sprayed on a spouting region on an upper surface of the substrate held by the substrate holding unit; and a protective liquid nozzle which spouts a protective liquid obliquely onto the upper surface of the substrate held by the substrate holding unit for protection of the substrate to cause the protective liquid to flow toward the spouting region on the upper surface of the substrate, whereby the spouting region is covered with a film of the protective liquid and, in this state, the treatment liquid droplets are caused to impinge on the spouting region.