Abstract: The present invention relates to electronics and especially to semiconductors. It is an improved embodiment of a luminescent diode, intended to increase the radiated power thereof. The device concerned is realized in the form of a securing device comprising a back plate and binding screws. The luminescent diode cover resembles a polyspherical lens with a cylindrical base having guide rods relative to the positionning openings provided in the back plate. The thickness of the back plate is equal to or larger than four thicknesses of light transmitter crystal. The crystal is fastened on the flat portion of the conical reflecting surface formed on the back plate. The depth of the conical surface exceeds two thicknesses of light transmitter crystal, and the resting area of the crystal has a diameter larger than the diagonal of its lower limit, but does not exceed the value of said diagonal by more than one and a half.