A time-resolved microfluorimeter with a synchroscan streak camera, which can be extended to a fluorescence lifetime imaging microscope (FLIM), has been developed for the use in biomedical research and clinical diagnosis. The schematic diagram of the instrument is given in Figure 1. The key idea for this instrument is to acquire molecular information on the structure of interest observed under the fluorescence microscope by using time-resolved fluorescence spectroscopy. The fluorescence lifetime is probably the only physical observable, the absolute value of which can be reliably determined in fluorescence microscopy.