A dielectric-film-type electron emitter includes an emitter section, a first electrode, and a second electrode. The emitter section is formed of a thin layer of a polycrystalline dielectric material. The dielectric material constituting the emitter section is formed of a material having high mechanical quality factor (Qm). Specifically, the dielectric material has a Qm higher than that of a so-called low-Qm material (a material having a Qm of 100 or less). The Qm of the dielectric material is preferably 300 or more, more preferably 500 or more.