We present first‐principles calculations of electron emission from an Al atom adsorbed on metallic jellium electrode using the first‐principles recursion‐transfer‐matrix (RTM) method with the nonlocal pseudopotential. The original boundary condition of RTM method is modified to express a constant electric field far into the vacuum region. We describe the details of the condition, and show the microscopic distributions of the electron emission current and the potential barrier for the system. © 2003 American Institute of Physics