We report computed results of the surface band structures of a molybdenum (001) surface by employing a self-consistent semirelativistic version of the full potential linearized augmented-plane-wave method. Computation was carried out for a seven-layer slab of bulk-truncated (1\ifmmode\times\else\texttimes\fi{}1) Mo(001) surface, ignoring the spin-orbit interaction. The resulting surface band structures are compared with recent experimental measurements at temperatures above and below a transition temperature. Despite general agreement with observation, we noted some characteristic differences in both energy and band connectivity. Details in both the electronic properties of surface states and resonances are examined and discussed in light of their significance for reconstruction mechanism.