A completely new near field mapping system based on micro monopole antenna has been developed in order to determine the electric near-field at the surface of MMIC. The possibilities of this innovative experimental setup are shown by 2D mapping of a bend 5 line deposited on GaAs substrate and a coupled-line filter on Duroid 6002. These are supported by 3D electromagnetic simulations. We finally give some results obtained on a real MMIC with a medium resolution of 50µm. The industrial applications are clearly the reliability issues of microwave power devices but also a new tool for MMIC designers. The knowledge of radiated near field will also contribute to optimize the packaging of microwave functions.