1. A pattern discrimination device comprising: an optical image acquisition unit configured to acquire both a transmissive image of a workpiece having a pattern and a reflective image of the workpiece pattern at a time; and a specific pattern detection unit configured to distinctly detect a specific pattern from among pattern shapes of the transmissive and reflective images in conformity with a discrimination condition of the specific pattern, wherein the discrimination condition of the specific pattern is based on the amount the size of the transmission image is smaller relative to the size of the reflection image for a cut pattern, or, alternatively, the amount the size of the reflection image is smaller relative to the size of the transmission image for a residue pattern.