ANTARES is an underwater telescope designed to search for high-energy neutrinos originating from extra-terrestrial sources. The detection principle relies on the observation of Cherenkov light emitted along the path of the charged leptons resulting from charged current neutrino interactions. The detector is a 3-dimensional array of photomultiplier tubes, arranged on twelve vertical lines (each housing 75 photomultipliers), placed at a depth of about 2500 meters 40 km off the coast of Toulon, France. The detector has been continuously collecting data in its full configuration since May 2008: at present 5 neutrino per active day are detected. In this talk a status of the detector operation will be provided and first results on the search for cosmic neutrinos, from point-like and diffuse sources, will be described.