In this paper a Monopole antenna is used for millimeter wave application. The proposed antenna consists of semicircular patch with microstrip feed. The antenna is supported with Spiral Artificial Magnetic Ground (AMC) instead of conventional Perfect Electric conductor (PEC) ground. The vias are created to get decrement in return loss. The option of AMC is chosen so that the effect of surface wave could be minimized. For these structures RT Duriod having relative permittivity of 2.2 and thickness of .45mm is used. The analysis of the antenna is done on the basis of simulation results, obtained using IE3D simulator of Zeland Corporation. © 2011 ISRAMT.