In a fluorescence measuring method and apparatus, a sample S is irradiated with
pulsed pumping light supplied from a pumping light source. Fluorescence generated
by the sample S is detected by a photodetector by way of a condensing optical system
and a spectroscope. The fluorescence time waveform is subjected to a data analysis
in a data processing unit in a controller. This computes waveform data and physical
quantities such as fluorescence lifetime. The pumping light time waveform is fixedly
arranged with respect to a time axis used for data analysis. Fitting calculations
are carried out while moving the fluorescence time waveform and fitting range from
an initial position earlier than a pumping light peak to a later end position,
and optimal measurement waveform data is selected according to a predetermined
selection criterion. Waveform data is thus computed accurately and efficiently
regardless of fluctuations in the fluorescence time waveform.
