One aspect of the invention relates to a pump device comprising an impeller; a pump housing surrounding an interior region and having an inlet and an outlet. The impeller is provided in the interior region of the pump housing. The wall of the pump housing has at least one first subregion and at least two further subregions in at least one plane perpendicular to the longitudinal extension of the pump housing. The at least one first subregion comprises at least 60% by weight, based on the total mass of the at least one first subregion, of at least one nonmagnetic material. The further subregions comprise at least 41% by weight, based on the total mass of the further subregions, of at least one ferromagnetic material, wherein each further subregion is adjacent to at least one first subregion in the plane.