The invention relates to an electronic ballast for a fluorescent lamp, the lamp load circuit being connected between the inverter power switch elements (S₁, S₂). The lamp load circuit comprises an inductor (L_R) in a series connection with the lamp. Prior to the ignition of the lamp, the lamp load circuit also includes a capacitor (C_R) in a series connection with the heating transformer primary winding (T_1a), this series connection being in parallel with the lamp. The heating current is supplied to the lamp cathodes solely via the heating transformer secondary windings (T_1b, T_1c), whereby the heating current can be shut off by way of setting a switch element (S₃) that is in parallel with the transformer primary winding (T_1a) in an ON condition. The heating current may be controlled to a desired level by driving the switch (S3) ON and OFF with a pulse-width-controlled drive signal.