Results of measurements of the diurnal wave of the cosmic ray (CR) intensity in stratosphere at the latitude with the geomagnetic cutoff rigidity R sub c = 7.6 GV are presented. Measurements of diurnal variation of the CR intensity were carried by means of radiosondes: by a detector composed of a gas discharge counter CTC-6 and a telescope containing two counters with a 7 mm aluminum filter between them.