PURPOSE: To obtain a height measuring apparatus which measures the height of a defect, which regards a height within a tolerance as a good product and whose yield is enhanced.

CONSTITUTION: The position of a defect D on an object A to be inspected is decided by an inspection device. Then, the defect D is monitored by a miscroscope 4 so as to be placed in the center of a monitor. Then, a laser beam is shone at the surface of the defect D by a light-emitting diode 2. Then, reflected light from the defect D is received by a position detection element 6, and a distance up to the surface of the defect D is measured by a signal processing circuit 7 on the basis of a signal from the position detection element 6. Then, the above operation is repeated in places on the surface of the object A, to be detected, other than the defect D, and a distance up to the surface of the object A to be inspected is measured. Then, the distance up to the defect D is subtracted from the distance up to the object A, to be inspected, by an arithmetic part 8. Thereby, the height of the defect D can be measured.