An electrosurgical instrument is provided for the treatment of tissue, theinstrument (3)comprising an instrument shaft (14) having a longitudinal axis, a suctionlumen (16)extending at least partially along the instrument shaft, and a chiselelectrode (21) at thedistal end of the shaft. The chisel electrode (21) includes a body portion(22) at a firstangle with respect to the longitudinal axis, and a hook portion (23) extendingfrom thebody portion at a second angle to the longitudinal axis. The chisel electrode(21) alsoincludes a plurality of apertures (35, 36, 37, 38, 40) providing a suctionlumen through theelectrode, there being at least one aperture (35, 36, 37, 38, 42) in the bodyportion (22),and at least one aperture (40, 45) in the hook portion (23).