A thin film electroluminescent panel includes a transparent substrate with an electroluminescent element formed on the substrate. There is a moisture proof sheet to cover the electroluminescent element. The moisture proof sheet includes a metal layer laminated between the two resin films. The periphery of the moisture proof sheet is adhered to the transparent substrate. There is a moisture proof sheet with a moisture absorbent powder thereon, located between the electroluminescent element and the moisture proof sheet. The combination prevents moisture from affecting the operation of the electroluminescent element and provides for stability.