Air disinfection device comprises a body that houses the power supply and control unit comprising a storage capacitor, a high-voltage DC power supply, an ignition pulse generator, a ferrite-core pulse transformer and a program control unit, and an ultraviolet radiation source mounted on the body in the form of a pulse gas discharge lamp enclosed in a tubular cooled casing transparent to bactericidal radiation. The storage capacitor and the pulse gas discharge lamp form a discharge circuit connected to the ignition pulse generator through the ferrite-core pulse transformer. The pulse gas discharge lamp is installed in a casing transparent to bactericidal radiation with convection air cooling capabilities provided by natural draft produced inside the casing, wherein the casing has one or several upper-level orifices in its upper part and some lower-level orifices in its lower part, with the following ratio of parameters:h·Supper2·Slower2Supper2+Slower2=1A·C2U04F2where h is the distance between the orifices of the upper and lower levels, m Supper—total surface area of the orifice in the upper level, m2 Slower—total surface area of the orifice in the lower level, m2 A=(2÷30)·1013J2/m5s2—power correlation coefficient C—capacity of energy storage capacitor, F U0—charge voltage of the energy storage capacitor, V F—pulse repetition rate of the ignition pulse generator, Hz.
