SUBSTRATE PROCESSING APPARATUS

A substrate processing apparatus includes a body which includes an upper face and side faces, and extends in a first direction, a plurality of robot arms which are installed on the upper face of the body, extend in the first direction, are spaced apart from each other in a second direction perpendicular to the upper face of the body, and are able to grip a wafer, and an alignment jig (JIG) which is installed on the upper face and side faces of the body, and senses positions of the plurality of robot arms, wherein the alignment jig includes, a horizontal frame disposed on the upper face of the body, a vertical frame disposed on the side faces of the body, and a displacement sensor installed on the horizontal frame and the vertical frame to sense coordinates of upper faces of the plurality of robot arms and side faces of the plurality of robot arms, the displacement sensor includes a first sensor and a second sensor which are spaced apart from side faces of the plurality of robot arms in a third direction perpendicular to the first and second directions and spaced apart from each other in the first direction, and an upper face of the displacement sensor is disposed at a vertical level higher than vertical levels of the upper faces of each of the plurality of robot arms.