A correction device for an optical measuring apparatus obtains correction data for each scanning position of a light beam from an optical measuring apparatus that includes a light beam scanner which scans with a light beam a measuring region where a measured object is placed, and a light receiver which receives a transmitted light beam from the measuring region. The correction device includes a translucent scale having scale marks arranged at a predetermined pitch, and a support to mount the scale in the measuring region so that an arrangement direction of the scale marks is a scanning direction of the light beam.