The phosphorescence microscope (i.e. a microspectrophosphorimeter) was used for recording the phosphorescence of microobjects. The general optical scheme of the reflecting phosphorescence microscope is described. The recordings of the phosphorescence spectra of cells of various types (bacteria, yeast, protozoa and human fibroblasts) were carried out both at room temperature and deep cooling. It will be shown that the phosphorescence spectra of the microorganisms are specific for every species of cells. The changes of the spectral parameters and triplet decay times after X-irradiation of Tetrahymena pyriformis cells were demonstrated. The decay time of phosphorescence of the fibroblasts at low temperature was also obtained.