The mechanical part includes (1) mirror holder, (2) mirror column, (3) mirror arm, (4) lens barrel, (5) objective converter (rotator), (6) mirror stage (stage), (7) adjuster.

The functions of the mechanical parts are: (1) mirror holder: base, supporting function; (2) Mirror column: connects the mirror base and mirror arm; (3) Mirror arm: the part of the hand that holds the microscope when taking and placing it; (4) Tube: The upper end of the tube is equipped with an eyepiece, and the lower end is equipped with an objective lens converter; (5) Objective lens converter (rotator): can exchange objectives of different magnifications; (6) Mirror stage (stage): used to hold glass slide specimens; (7) Adjuster: Move the stage up and down.

The functions of the lighting part are as follows: (1) Reflecting mirror: Its function is to reflect the light from the light source onto the condenser, and then illuminate the specimen through the light hole; (2) Concentrator: Its function is to concentrate light onto the specimen to be observed.

The functions of the optical part are as follows: (1) Eyepiece: observing and magnifying the object image, the length of which decreases with the increase of magnification; (2) Objective lens: Observing magnified objects, its length increases with the increase of magnification.

Optical microscopes usually consist of an optical part, an illumination part, and a mechanical part. Undoubtedly, the optical part is the most crucial, consisting of an eyepiece and an objective lens. As early as 1590, Dutch and Italian eyeglass manufacturers had already created magnifying instruments similar to microscopes. There are many types of optical microscopes, mainly including bright field microscopes (ordinary optical microscopes), dark field microscopes, fluorescence microscopes, phase contrast microscopes, laser scanning confocal microscopes, polarizing microscopes, differential interference microscopy, and inverted microscopes.