PURPOSE: To provide a fluorescent display tube emitting bright red light by low- energy electron beam excitation, and having a light-emitting layer composed of a low-resistance material based on zinc oxide and a specific fluorescent material.

CONSTITUTION: A light-emitting material is prepared by mixing (A) 1 part by weight of a low-resistance material composed mainly of zinc oxide, and (B) 14:1W 1:14 parts of one or more fluorescent materials selected from (a) yttrium/lanthanum/gadolinium oxide fluorescent material doped with europium, (b) yttrium/lanthanum/gadolinium sulfide fluorescent material doped with europium, and (c) yttrium/lanthanum/gadolinium vanadate fluorescent material doped with europium. A glass plate 2 is coated with the light-emitting material thus obtained to form a group of anodes 3aW3n, and a cathode filament 4 is disposed opposite to the anodes. A group of control mesh grids 5aW5n are placed between the anodes and the cathode. The glass plate 2 is bonded to a transparent front glass 1 to form a vessel, which is evacuated, tipped off, and gettered to attain a high vacuum.