A vacuum fluorescent display includes a vacuum tube with a pair of substrates, and a side glass disposed between the two substrates. Filaments are mounted within the vacuum tube to emit thermal electrons. A conductive layer is formed at one of the substrates with a predetermined pattern, and a phosphor layer is formed on the conductive layer. A rib grid is provided at the substrate with an insulating rib positioned around the conductive layer, and a control electrode is formed on the top surface of the insulating rib. Assuming that the distance between the top surface of the substrate and the top surface of the insulating rib is indicated by h1, and the distance between the top surface of the substrate and the top surface of the phosphor layer is indicated by h2, it is established that h1nullh2.