A wafer perforating device includes a chuck stage configured to receive a wafer, a housing spaced apart in a vertical direction on the chuck stage, wherein at least one of the housing and the chuck stage moves in a first horizontal direction, and the housing and the chuck stage intersect each other on the first direction, a displacement sensor fixed within the housing and configured to measure a displacement with a surface of the wafer at a perforating point spaced apart periodically in the first direction of the wafer and a laser module fixed within the housing and configured to irradiate a laser into a perforating depth determined according to the displacement at the perforating point. The displacement sensor determines whether an upper particle and a lower particle are present at the perforating point by considering a step height of the displacement, and ignores the displacement of the perforating point with the presence of an upper particle.