Scanning Electron Microscopes (SEM)

Transmission Electron Microscopes (TEM)

Electron stream

Fine, focused beam

Broad beam

Image taken

Topographical/surface

Internal structure

Resolution

Lower resolution

Higher resolution

Magnification

Up to 2,000,000 times

Up to 50,000,000 times

Image dimension

3-D

2-D

Sample thickness

Thin and thick samples okay

Ultrathin samples only

Penetrates sample

No

Yes

Sample restriction

Less restrictive

More restrictive

Sample preparation

Less preparation required

More preparation required

Cost

Less expensive

More expensive

Speed

Faster

Slower

Operation

Easy to use

More complicated; requires training