Extra cellular electrical recording of the central nervous system has been used for decades by electro-physiologists to explore fundamental properties of neural networks. Thanks to the evolution of micro-technology, it is now possible to develop a new kind of Micro Electrode Array (MEA) that can be used for in vitro and in vivo applications, both to record and stimulate neuronal tissues. This paper describes an alternative approach compared to classical MEA process based on the use of a non conventional material, namely Boron Doped Diamond (B-NCD), to fabricate different kind of MEAs. We first present the specific technology developed to fabricate diamond based MEA, and then second the fabrication of the MEAs with some characterisation results. We show that B-NCD offers several advantages when compared to metallic materials, especially excellent biocompatibility. We finally introduce first results concerning the application of such diamond based MEAs to retinal implants.