The present invention relates to a plasma-generating device, comprising an anode, a cathode and a plasma channel which in its longitudinal direction extends at least partly between said cathode and said anode. The end of the cathode which is directed to the anode has a cathode tip tapering towards the anode, a part of said cathode tip extending over a partial length of a plasma chamber connected to the plasma channel. The plasma chamber has a cross-sectional surface, transversely to the longitudinal direction of the plasma channel, which exceeds the cross-sectional surface, transversely to the longitudinal direction of the plasma channel, of an opening, positioned closest to the cathode, of the plasma channel. The invention also concerns a plasma surgical device and use of such a plasma surgical device.