  We investigated the superconducting fluctuation in FeSe, which is assumed to
be located in the BCS--BEC crossover region, via magnetic torque measurements.
In our method, the absolute cantilever displacement is measured by detecting
the interference intensity of the Fabry--Perot cavity formed between the
cantilever and optical fiber. Our findings are totally different from the
results of the previous torque magnetometry using a piezoresistive cantilever;
the "giant" fluctuation diamagnetism related to the BCS--BEC crossover does not
exist. Instead, a considerably smaller fluctuation signal originating from the
vortex liquid was observed that showed a qualitatively similar behavior to
those in cuprate superconductors. We also discuss the inconsistency between our
torque data and the existence of a pseudogap proposed by an NMR experiment.
