The invention is directed to detect a warp amount in a real-time manner in a wafer rotating at high speed under inspection. An inspection apparatus includes: a first light irradiating unit for irradiating an object to be inspected with light; a first detector for detecting scattered light from the object to be inspected; a second light irradiating unit for irradiating the object to be inspected with light; a second detector for detecting light reflected from the object to be inspected, of light of the second light irradiating unit; a stage for moving an object to be inspected, which moves the object to be inspected so as to change irradiation positions on the object to be inspected, of the light of the first light irradiating unit and the light of the second light irradiating unit; an inspection coordinate detector for outputting information of coordinates of a position irradiated with light; an elevation control circuit for outputting height information of the object to be inspected on the basis of a detection signal from the second detector; and a data processing unit for calculating a warp amount of the object to be inspected on the basis of the information of the position coordinates from the inspection coordinate detector and the height information from the elevation control circuit.