Abstract: Straight tracks are formed in a first direction on a base. The top surface of a platform is formed so as to be flat to mount a wafer having an Ori-Fla, and the platform is moved in the first direction by being engaged with the straight tracks via engagement means. A block having a flat face against which the Ori-Fla of the wafer abuts and which is parallel with the first direction is installed with a first clearance L being provided with the straight track in a second direction perpendicular to the first direction. Wafer fixing means for fixing the wafer in a state in which the wafer is mounted on the platform is provided in the platform, and a measurement device having a probe opposed to the straight track and capable of being displaced in the second direction is installed on the base with a second clearance M being provided with the block in the first direction. When a clearance between the tip end of the probe and the straight track is taken as N, the relationship of 0 ?m<L?N?100 ?m exists.

Abstract: Straight tracks are formed in a first direction on a base. The top surface of a platform is formed so as to be flat to mount a wafer having an Ori-Fla, and the platform is moved in the first direction by being engaged with the straight tracks via engagement means. A block having a flat face against which the Ori-Fla of the wafer abuts and which is parallel with the first direction is installed with a first clearance L being provided with the straight track in a second direction perpendicular to the first direction. Wafer fixing means for fixing the wafer in a state in which the wafer is mounted on the platform is provided in the platform, and a measurement device having a probe opposed to the straight track and capable of being displaced in the second direction is installed on the base with a second clearance M being provided with the block in the first direction.