Defect inspection device of steel plate

Provided is a defect inspection device of a steel plate. The defect inspection device according to the present invention includes a plurality of inspection units arranged in a width direction of the steel plate, wherein each of the plurality of inspection units includes a first magnetized pole and a second magnetized pole corresponding to each other. Also, the inspection unit includes: a magnetizing part generating a magnetic flux for magnetizing the steel plate in a direction inclined at a predetermined angle with respect to a rolling direction through the first magnetized pole and the second magnetized pole; and a detection part detecting a leakage flux that leaks due to defects existing in or on the steel plate by using the flux generated by the magnetizing part. Thus, the defects may be correctly detected through the defect inspection device.