The present invention provides a diamond electron source exerting stable and excellent electron emission characteristics, which can be used for a cold cathode surface structure operable with low voltage and a method for producing the diamond electron source. Specifically, the diamond electron source having a carbon-terminated structure has a structure composed of an electrode and a diamond film and emits electrons or electron beams from the diamond film when voltage is applied to the electrode. The diamond film is made of diamond having a carbon-terminated structure. The method for producing the diamond electron source is also provided herein.