The steel material for an impact absorbing member has a composition containing: by mass %, C: 0.05 to 0.18%, Mn: 1 to 3%, Si+Al: at least 0.5% and less than 2.5%, and N: 0.001 to 0.015%, and in some cases, Cr: at most 0.5%, Mo: at most 0.2%, Ti: at most 0.05%, Nb: at most 0.05%, V: at most 0.2%, and B: at most 0.002%, the remainder being Fe and impurities. The steel material structure contains at least 70% by area of bainite made up of a lath structure having an average interval of at most 1 mm and martensite, 5 to 30%, and satisfies Formulas (1) and (2): (1) 1.2 £ HM0/HB0 £ 1.6, (2) 0.90 £ {(HM10/HM0)/(HB10/HB0) £ 1.3, where HM0 and HM10 represent average nano hardness in an initial state and after 10% tensile deformation of the martensite, and HB0 and HB0 represent that of bainite, respectively.