A substrate processing apparatus includes a rotary cup that is provided at a substrate holding unit to surround a substrate held thereon and to be rotated along with the substrate holding unit, and configured to guide a processing liquid dispersed from the substrate; and an outer cup that is provided around the rotary cup with a gap therebetween and configured to collect the guided processing liquid by the rotary cup. Further, a height of an upper end of the rotary cup is higher than that of the outer cup. Furthermore, an outward protrusion protruded outwards in a radial direction thereof and extended along a circumference thereof is provided at an upper end portion of an outer surface of the rotary cup, and the outward protrusion blocks mist of the processing liquid dispersed from the gap between the rotary cup and the outer cup toward a space above the substrate.