The ISO camera (ISOCAM) is an instrument designed to map selected areas of the sky in the spectral region from 2.5 to 17 μm at various spatial and spectral resolutions, polarization mapping will also be possible. At 10 μm the sensivity limitation ( lmJy in 10 min) will be mainly that imposed by the astronomical background. Spatial resolution will be limited to a few arcseconds by diffraction in the telescope and by the satellite pointing. A very wide range of astrophysical problems can be tackled with ISOCAM. Examples of current interest include : a systematic search for and survey of circumstellar disks or proto-planetary clouds, a probe for dark matter in the form of low mass stars, the nature and distribution of the emitters of the 'unidentified' (PAH?) infrared features, the low mass end of the initial mass function in star-forming regions ; mapping nearby galaxies. ISOCAM will provide imaging capability across a 3 arc min field of view with two arrays of 32x32 infrared detectors. Each array is mounted in one optical channel : the short wavelength channel operates in the 2.5 to 5.5 μm wavelength range with an InSb CID array, made by la Societe Anonyme des Telecommunications ; the long wavelength channel operates from 4 to 17 μm, with a Si:Ga direct read out array (DRO) made by LETI-LIR. Different magnification factors for matching the fixed pixel size to the desired pixel field of view on the sky are provided by four different lenses, which are mounted on a wheel. Choice of 1.5, 3, 6 or 12 arcsec. are possible, thereby determining the spatial resolution of the camera. The spectral range of the observations can be selected in each channel by a set of about 10 fixed band-pass filters and Continous Variable Filters (CVF), all mounted on a wheel. The spectral resolution is about 50 for the CVF and ranges from 2 to 100 for the filters. ISOCAM is being developped by an european consortium of laboratories led by the Service d'Astrophysique of CEN Saclay.