A cryopump having a generally axially symmetrical housing provided at one end with an entrance opening defined by a plane for passage of molecules of the gas to be pumped and plates defining condensation surfaces arranged to be brought to low temperature for condensation of molecules of the gas to be pumped, and a thermal radiation shield disposed in the region of the entrance opening, with the condensation surfaces being oriented substantially at right angles to the plane of the entrance opening and the radiation shield being composed of a plurality of elongate metal strips so positioned that their longitudinal axes are parallel to the condensation surfaces.
