We have investigated the primary process of the carrier generation in Y-form titanyl phthalocyanine (Y-TiOPc) microcrystallites by means of newly developed electric-field-modulated picosecond time-resolved fluorescence spectroscopy. Two singlet excitons have been identified in the fluorescence decay curves of Y-TiOPc. We have inferred from the field-dependence of the fluorescence amplitudes and lifetimes that the shorter-lifetime exciton of intramolecular charge transfer (CT) character is a primary intermediate in the carrier generation process. It has been found that the internal conversion from the CT exciton to the Frenkel exciton is decelerated by the electric field.