The present invention is directed to a method for cleaning a section of an optical waveguide removed from its jacket, in which the optical waveguide section is inserted into a treatment cell, sprayed with a cleaning fluid, blasted with compressed air and removed from the treatment cell. The method allows cleaning in precisely defined conditions, which can be carried out in a simple fashion in a corresponding device. The blasting of the optical waveguide section with compressed air preferably first includes the use of heated compressed air and then the use of cold compressed air. The present invention is also directed to a cleaning device with a treatment cell to hold the optical waveguide section, the treatment cell having a first inlet for the supply of compressed air, a second inlet for the supply of cleaning fluid and an outlet for the removal of compressed air and cleaning fluid. The cleaning device is preferably configured as a system that is isolated from the environment, so that the escape of possibly toxic liquid or vaporous cleaning agents and therefore any danger to the health of an operator is reliably excluded.