<p>A device is provided for fracturing a geological hydrocarbon reservoir including two packers defining between them a confined space in a well drilled in the reservoir; a pump for increasing the pressure of a fluid in the confined space; an apparatus for heating the fluid; at least one pair of two electrodes arranged in the confined space; and an electric circuit for generating an electric arc between the two electrodes, the circuit including at least one voltage source connected to the electrodes and an inductance between the voltage source and one of the two electrodes. The device permits improved fracturing of the reservoir.</p>