A backlight 23 of the present invention has a panel case 24 and plural phosphor-coated anode sections 25 each arranged flatly in the panel case and plural linear cathode sections 26. Each of the plural linear cathode sections 26 has a conductive wire 33 having a great number of field concentration assisting concave/convex sections 34 formed on its outer peripheral surface and a carbon-based film 35 having, as a field electron emitter, a great number of sharp microscopic sections on the field concentration assisting concave/convex sections 34, wherein the field electron emitter emits electrons toward each of the plural phosphor-coated anode sections 25 so as to be radially widespread, when DC voltage is applied between the phosphor-coated anode sections 25 and the linear cathode sections 26.