The Physics of the Accelerating Universe (PAU) collaboration aims at conducting a competitive cosmology experiment. For that purpose it is building the PAU Camera (PAUCam) to carry out a wide area survey to study dark energy. PAUCam has been designed to be mounted at the prime focus of the William Herschel Telescope with its current optical corrector that delivers a maximum field of view of ~0.8 square degrees. In order to cover the entire field of view available, the PAUCam focal plane will be populated with a mosaic of eighteen CCD detectors. PAUCam will be equipped with a set of narrow band filters and a set of broad band filters to sample the spectral energy distribution of astronomical objects with photometric techniques equivalent to low resolution spectroscopy. In particular it will be able to determine the redshift of galaxies with good precision and therefore conduct cosmological surveys. PAUCam will also be offered to the broad astronomical community.