Provided are an antibody capable of specifically and accurately measuring digested products of stabilized fibrin (D-dimer), and a method and a reagent for measuring D-dimer using the antibody. The antibody specifically reacts with D-dimer, which is plasmin-digested products of stabilized fibrin, but does not react with fibrinogen or plasmin-digested products of fibrinogen, which include fragment X, fragment Y, fragment D1, and fragment E3, and does not react with dissociation products of DD/E monomer, which include fragment DD, fragment E1, and fragment E2.