Abstract: The present invention provides a carbon film that is remarkably excellent in current voltage (IV) characteristics. This is achieved by way of a carbon film structure, two or more carbon film assembly units 12 are formed on a substrate 10. The carbon film assembly units 12 comprise: a stem-like carbon film 14 which is made into a film in the shape of a long and thin needle; and a branch-like carbon film cluster 16 which is made into a film so as to surround the stem-like carbon film 14 from the halfway to the lower part of this stem-like carbon film 14. The stem-like carbon film 14 has the shape of a long and thin needle having a configuration which has a spiral streak-like step part 18 towards the distal end at the circumference face of a near tip and in which the radius becomes small as going to the distal end.

Abstract: An electron emitter includes a guard electrode 13 on the outer circumferential side of a carbon film structure 10 which is formed on a substrate 7 by plasma CVD method. This guard electrode 13 includes a curved surface portion (a curved surface portion that curves from top toward a side opposite to the film-forming direction) 13a convex in a film-forming direction of the carbon film structure 10. A curvature radius R1 of an outer-circumferential-side portion of the curved surface portion 13a is larger than or equal to a curvature radius R2 of a carbon-film-structure-side portion of the curved surface portion 13a.

Abstract: The present invention provides a carbon film that is remarkably excellent in current voltage (IV) characteristics. This is achieved by way of a carbon film structure, two or more carbon film assembly units 12 are formed on a substrate 10. The carbon film assembly units 12 comprise: a stem-like carbon film 14 which is made into a film in the shape of a long and thin needle; and a branch-like carbon film cluster 16 which is made into a film so as to surround the stem-like carbon film 14 from the halfway to the lower part of this stem-like carbon film 14. The stem-like carbon film 14 has the shape of a long and thin needle having a configuration which has a spiral streak-like step part 18 towards the distal end at the circumference face of a near tip and in which the radius becomes small as going to the distal end.