A light-emitting element driving apparatus, method and projector are provided, in which a common power supplying section drives plural light emitting elements of different rated current in a time sharing driving manner whereby the light emitting elements emit light stably.The light-emitting element driving apparatus comprises a direct-current power source 12 for supplying direct current I-in, a light-emitting element selection controlling section 11 for selecting light emitting elements 10R, 10G, 10B of different rated current, successively, a power supplying section 13 for changing the direct current supplied from the direct-current power source 12 to predetermined output current and supplying the output current I-out to the light emitting element selected by the light-emitting element selection controlling section 11, and a connection controlling section 15 for connecting one subsidiary capacitor among subsidiary capacitors 14R, 14G, 14B in parallel with one appropriate light emitting element out of the light emitting elements 10R, 10G, 10B at a predetermined timing.