A very simple, clean, and effective method based on a reliable machining process called electrical discharge machining (EDM) was introduced in order to enhance the field emission uniformity of carbon nanofibers (CNFs). After an EDM post-treatment, the uniformity of the CNF emitters was clearly improved without contaminations, damages, or crystalline deteriorations of the CNFs. As a result, field emission uniformity was apparently enhanced at a low electric field range, promising that the method can be practical for applications requiring both large size and fine uniformity such as in a backlight unit.