An immersion microscope objective includes a system of several optical lenses or lens groups between which air spaces are provided and an adjusting device for adapting the immersion microscope objective to different immersion mediums for correcting imaging errors when utilizing the immersion microscope objective in connection with a cover glass, which closes off a specimen holder, and/or for correcting longitudinal chromatic aberrations. The adjusting device is configured to change two air spaces and especially the air spaces (A1, A2) are linearly changeable.