To provide an optical measuring apparatus, an optical measuring method, and an optical measurement processing program which allows lateral correction.

The optical measuring apparatus 1 is provided with: a light sending unit 3 which forms a beam LB2 focusing in a measurement area R in which an object under measurement W is placed and scans the beam LB2 in the measurement area R; a light receiving unit 5 which receives the beam LB2 passed through the measurement area R and outputs a light reception signal Sg on the basis of the received beam LB2; and a control unit 7 which calculates a measured value D indicating the dimension of the object under measurement W on the basis of the light reception signal Sg. The control unit 7 corrects the measured value D on the basis of a change in the intensity of the light reception signal Sg with respect to a unit time for scanning the beam LB2.