The invention relates to a treating device (1) for treating a body part of a patient with a non-thermal plasma, particularly for sterilizing a hand of a human being, said treating device (1) comprising a housing (2) for temporarily receiving the body part within the housing (2) during the treatment and for applying the plasma to the body part within the housing (2), and an inlet opening (3) being arranged in the housing (2) for introducing the body part through the inlet opening (3) into the housing (2). (Figure 3)