An apparatus and method incorporating at least two sensors that detect the presence of substrate defects, such as breakage or misalignment, along the lengths of at least two parallel edges of a moving substrate. In one embodiment, an apparatus for detecting substrate defects includes a sensor arrangement including at least two sensors that continuously sense a substrate near at least two parallel edges of the substrate as the substrate passes the sensors. In another embodiment, an apparatus for detecting substrate defects includes a robot having a substrate support surface, and a sensor arrangement including at least two sensors that continuously sense a substrate near at least two parallel edges of the substrate during substrate transfer on the substrate support surface. In another embodiment, a method of continuously detecting substrate defects includes positioning at least two sensors to continuously sense a substrate near at least two parallel edges of the substrate as the substrate passes the sensors, and transmitting a signal from each of the at least two sensors to a controller that continuously monitors the signals from the at least two sensors to detect the presence of a substrate defect.