The invention relates to a driving apparatus for a CCFL capable of providing a high output voltage necessary for an open lamp and thereby satisfying a voltage standard required to drive the lamp. In the driving apparatus, an inverter made of a switching circuit of a half-bridge structure is used to generate current for driving the lamp. If the lamp is open, a tuning capacitor current of an oscillator, which provides a reference clock for driving a switch of the inverter is incremented so that a clock frequency which is a basis for a switching speed of the inverter is boosted. This consequently increases the switching speed of the inverter and then an output voltage.