A microscope including an objective, which images a sample along a microscope beam path, and an autofocus device, which is coupled into the microscope beam path via a beam splitter at a location behind the objective. A light modulator for generating a two-dimensional, intensity-modulated modulation object, is located in the autofocus beam path in a plane conjugated to the focal plane of the objective or intersects the latter and is imaged into the focal plane of the objective. A camera records a two-dimensional image onto which the modulation object's image is imaged. The image plane of the camera intersects a plane that is conjugated to the modulation object or is located in the plane and the camera detecting the contrast of the modulation object's image located in the sample.