A workpiece processing apparatus includes: a first rotational distance information storage unit that stores multiple pieces of first rotational distance information, each of which is information having, in association with each other, a rotational angle, and first distance information regarding a distance from a rotation center to an edge of a circular workpiece corresponding to the rotational angle, in a case where the workpiece is rotated; an acquiring unit that acquires information for positioning the workpiece, information for specifying an orientation of the workpiece, and information regarding a defective portion at the edge of the workpiece, using the multiple pieces of first rotational distance information stored in the first rotational distance information storage unit; and an output unit that outputs the information for positioning the workpiece, the information for specifying the orientation of the workpiece, and the information regarding the defective portion, which are acquired by the acquiring unit.