To obtain a compact package with improved radiation shielding ability and good moldability by mixing heavy metal powder and binder material powder in an arbitrary ratio and holding the mixture at the temperature for dissolving the binder material powder in vacuum or in an inert gas atmosphere and then molding and solidifying it into an arbitrary shape.

Powder 1 of a heavy metal (or one with nickel plated on the surface thereof) such as tungsten having high radiation shielding power and powder 2 of a binder material such as lead, iron, etc., are mixed in a ball mill, etc., in an arbitrary ratio, and then the mixed powder is put in a mold, etc., and is held for an arbitrary time period at the temperature for dissolving the binder material powder. In this case, vacuum or an inert gas is used as the heating atmosphere depending on the material used. Consequently, the mold is pressed to solidify the mixed powder and is cooled to manufacture a blank. Thus, a compact package with improved radiation shielding ability and good moldability can be obtained.