This paper presents a family of integrated circuits quite specific : the Monolithic Microwave Integrated Circuits. The MMIC have very special design and manufacturing processes because of the raw material technology (mainly Gallium Arsenide: GaAs) and the frequency bands used (commonly from 1 to 100 GHz) for which the design tools are still limited. The MMICs mainly originated in response to the needs of the military industry for miniaturization. They offer today attractive solutions for new commercial and professional products in Telecommunications, Broadcasting, Positioning... The following presentation is focussing on these three items: technology, design and applications.