Abstract: A carriage mechanism for horizontally carrying a rectangular shaped substrate and a gas injection mechanism for jetting a gas toward both upper and lower surfaces of the carried rectangular shaped substrate are provided and an air from a gas injection port is jetted on the substrate toward a center portion from both ends of the substrate, wherein by means of the high pressured air jetted from the gas injection port of the gas injection mechanism, droplets are collected from both end surfaces of the substrate and collected at the center portion of the substrate where the air concentrates, and the collected droplets are blown away from the end surfaces of the substrate with the help of surface tension of the substrate also.