Abstract
An electron energy loss spectrometer for a medium voltage electron microscope has been developed. The spectrometer has a double dispersion lens which is set behind the magnetic prism in order to magnify energy loss spectra. The chromatic focus shift of the dispersion lens is corrected electrically; therefore, energy loss spectra of high energy resolution over a wide energy range can now be obtained. Also, the spectrometer has an object point at the cross-over-point of the projecter lens; therefore, it is convenient to analyze a microarea of the specimen exactly corresponding to the object field in the image. The performance of the spectrometer has been ascertained by using practical specimens.