Who invented the microscope and discovered microorganisms?

Dutch spectacle maker Zacharias Janssen invented the first so-called compound microscope in 1590.

Later, Dutch scientist Antoine van Leeuwenhoek designed high-powered single lensed microscopes, (also known as a simple microscope) in 1670. Using his simple microscope he was the first to describe sperm cell or spermatozoa.

The existence of microorganisms was discovered by Robert Hooke and Antoni van Leeuwenhoek during the period 1665-83 (17th century).