A micro electrical and/or electronical device, as in particular a hearing aid being worn e.g. behind the ear, is characterized by a housing shell (1), which at least partially comprises a skid-proof surface (11). This skid-proof surface can be made out of an elastomeric polymer or an elastic polymer. Preferably such part (11) of the surface of the housing or shell (1) is being made skid-proof, which is in contact with the skin, while wearing the hearing aid.