Abstract: A cleaning system for cleaning a surface is proposed, the cleaning system having: a cleaning tool (2) with a working region (A) and with a UV-light source (7), the UV-radiation of which emerges from the tool (2) in the working region (A), and a cleaning agent which contains a photoactivatable semiconductor material (3), UV-radiation being fed directly into the photoactivatable semiconductor material (2) in the working region (A) via a light guide device (9, 14).