The credit for building the first very primitive microscope is generally given to Zacharias Janssen, a Dutch spectacle maker. While there's some debate about who truly invented the microscope, Zacharias Janssen is often cited as the first to combine lenses in a tube to create a magnifying device around the year 1590.

It's important to note that:

* The exact inventor is uncertain. Some historians believe his father, Hans Janssen, may have been involved, and there are claims that Cornelis Drebbel, another Dutch inventor, also developed a similar device around the same time.

* These early microscopes were very simple. They consisted of two lenses in a tube and provided limited magnification.

Despite the uncertainty, Zacharias Janssen is the most commonly recognized figure associated with the invention of the first primitive microscope.