Provided is a polyurethane resin for a water equivalent phantom material having high water equivalence and excellent mechanical strength and flexibility. The present invention is a polyurethane resin for a water equivalent phantom material and a molded article of the polyurethane resin for a water equivalent phantom material which is a molded product of the polyurethane resin for the water equivalent phantom material, wherein a polyurethane resin is a reactant of a polyurethane resin forming composition that contains an inorganic filler and consists of polyol, polyisocyanate, and elements of atomic numbers 1-40, and wherein an effective atomic number (n) determined by general formula (1) is 7.0-8.0. It is preferable that the polyurethane resin forming composition further contains an organic filler.
