In a method for the fluorescence spectroscopic, in particular fluorescence correlation spectroscopic study of a measurement sample, the latter is introduced into a sample holding chamber (12) formed hollowed in a sample support (10). Electrically charged analytes contained in the measurement sample are then concentrated in a measurement volume (26) lying inside the sample volume, whereupon the measurement volume (26) is studied. According to the invention, the boundary walls (28) of the sample holding chamber (12) are brought essentially surface-wide to an electrostatic potential having the same sign as the charge of the analytes in order to concentrate the analytes in the measurement volume (26). An electrical molecule trap formed in this way can be produced very straightforwardly and is suitable in particular for screening studies of measurement samples, a large multiplicity of which are arranged close together in indentations (12) of the sample support (10).