The present invention concerns an electro-chemical surgical knife comprising in a single instrument both chemical and electrical separating functions. The chemical separating function is provided by:• a source, 7, of cleavage solution,• a pump, 8, for feeding the cleavage solution to,• a channel, 2, for transporting the cleavage solution to the operating location, and• a flow controller, 8c, for controlling the volumetric feeding of cleavage solution by the pump to the channel inlet.The electric cutting function is provided by:• A source of high frequency AC electrical power, 5, for feeding AC current through• An electric conductor, 3, to,• An electrode, 6, and further comprises• A second controller, 5c, for controlling the feeding of electric current to the electrode.
