Abstract: We have investigated the electron transport properties of a N₂₄B₂₄ molecule coupled to two metallic contacts with a combination of GW approximation and the non-equilibrium Green's-function technique. The calculations indicate that the four and three resonant tunneling peaks are seen for the density of states (DOS) curves in the cases of single and multiple atomic contacts, respectively. The off state and negative di erential resistance (NDR) effect are observed in the I-V characteristics of the N₂₄B₂₄ molecule. The NDR behavior is also observed in voltages of about ∓4.5, ∓4, ∓4.6, and ∓4.3 V for one, four, six, and eight atomic contacts. Also, the I-V characteristics of N₂₄B₂₄ are in off state at low voltages that is independent of the contact types. The current curves against the gate voltage depend on contact types and indicate that N₂₄B₂₄ molecule behaves as a semiconductor.