What is the maximum magnification of a SEM?

A scanning electron microscope has a very large depth of field which makes the images produced appear three dimensional. Magnifications from 25X to 250,000X (250 times the magnification limit of a light microscope) are possible.

Although my Science Text book says it can reach a magnification of 300 000X, but most specimens are easier to view at magnification less than 10 000X.