Automatic focusing control method for microscope

An automatic focusing control method for microscope includes preliminarily determining and storing respective in-focus positions of an objective lens of the microscope for a plurality of points on a stage of the microscope prior to observation and measurement of a sample by the microscope. Upon actual measurement after the sample has been mounted on the microscope stage, an approximate in-focus position of the objective lens for the sample is determined on the basis of the stored in-focus positions of the objective lens for at least one of the plurality of points in the vicinity of the sample. Then, the objective lens is moved to the determined approximate in-focus position at a high speed, and a usual automatic focusing is thereafter carried out, thereby making it possible to perform the automatic focusing operation rapidly and accurately.