It was previously proposed that porous diamond membranes can be used as held emission arrays. As main features of such a device, we identified a field enhancement factor equivalent or superior to that of a metal edge emitter, allied to a higher vacuum conductance. Emitting membrane prototypes were built and tested. These showed promising emission performance. In this work we continue the membrane pore characterization from a geometric point of view. Pie also present photoemission electron microscopy images from the emitting area around a pore. These images show that indeed there is enhanced electron emission occurring in that region. Current versus time and current versus field graphs complete the emission characterization.