The invention relates to a fixing device for fixing a soldering nozzle to a soldering device, comprising a front working end and a rear, fixing end, said ends being opposite each other. The soldering device has a connecting end to which said fixing end is fixed. A rotationally symmetrical section is arranged at at least one end. The aim of the invention is to provide a secure, simple, detachable means of fixing a soldering nozzle in a soldering device, using a simple construction. To this end, one end has a cone-shaped section which is configured with an outer cone, said outer cone being arranged at least in places in a peripheral direction and being eccentric in relation to the rotationally symmetrical section. The other end is configured with an inner cone, the outer cone being arranged in said inner cone in such a way that the outer cone is able to rotate between an insertion position and a fixing position.