Electrostatic Adhesion (ESA) was chosen as the surface attachment mechanism for Wall Climbing Robot (WCR) for its qualitative advantages. ESA model was developed to account for both parallel-plane and fringing static fields. Such Electrostatic Pad model yields equations governing the ESA force and the geometrical conditions for maximum ESA pressure per pad area. This paper shows that the parameters due to applied voltage, and also geometrical properties, material properties and compliance to wall surface of the Electrostatic Pad do affect the ESA force. The simulation also shows that fringing fields may account up to above 10% of total generated ESA force.