A microscope is an optical instrument composed of a lens or a combination of several lenses, which is a sign that mankind has entered the atomic age. Microscopy is an instrument mainly used to magnify tiny objects that can be seen by the human eye. Spectroscopic spectroscopy and electron microscope: The optical microscope was pioneered in 1590 by Jensen of the Netherlands. The current optical microscope can magnify the object 1600 times, the minimum limit of resolution is up to 1/2 of the wavelength, and the length of the domestic microscope mechanical tube is generally 160 mm. The person who made great contributions to the development of microscopy and microbiology was Leeuwenhoek, a Dutchman.