Experiments on mice were made to study the release to blood of exogenously injected glucose. It was established that this process was of rhythmical nature. Two periods of intense glucose release to blood were recognized: the maxima were attained at 4 and 12 o'clock. At other times glucose release to blood was negligible. It is assumed that oscillations in question are determined by the biological rhythms of glucose absorption by cross-striated muscle cells. Electromagnetic field altered the biological rhythms of glucose absorption by the muscles and raised glucose absorption. Mice with unmarked insulin deficiency preserved the tendency toward rhythmical changes in glucose release to blood, although muscle absorption of glucose was lowered.