The present invention relates to a wiper rubber (10) for a windshield wiper, comprising a wiper rubber substructure (1) with a wiper lip section (2) and a reinforcement section (4), the wiper rubber substructure (1) being uncoated and being formed from ethylene-propylene-diene rubber and/or ethylene-propylene rubber. In order to improve the wear resistance, wiping characteristics and wiping quality of the wiper rubber (10), the surface of the wiper rubber substructure (1) at least in a partial region (2c, 2c′) of the wiper lip section (2) has been treated with ultraviolet radiation. The present invention further relates to a process for producing a wiper rubber, to a correspondingly produced wiper rubber and to a windshield wiper equipped therewith.