Abstract: The principle, design and test results of a domestically made high-energy electron gun are described. It consists mainly of a filament, electromagnetic focusing lens, electromagnetic deflection lens, differential vacuum pumping unit, and power supply. It is capable of producing high energy electrons up to 30keV. The electron beam can be deflected more than 5° and the beam size focused to less than 100μm. The acceleration voltage is found to be directly proportional to the emission current. Details of the design and test results are reported.