A wafer polish monitoring method and device for detecting the end point of the polishing of a conductive film with high precision and accuracy by monitoring the variation of the film thickness of the conductive film without adverse influence of slurry or the like after the film thickness of the conductive film decreases to an extremely small film thickness defined by the skin depth. A high-frequency transmission path is formed in a portion facing the conductive film on the surface of the wafer, the polishing removal state of the conductive film is evaluated based at least on the transmitted electromagnetic waves passing through the high-frequency transmission path or the reflected electromagnetic waves that are reflected without passing through the high-frequency transmission path, and the end point of the polishing removal and the point equivalent to the end point of the polishing removal are detected.