We propose to use ISOCAM to map the dust emissivity in some young post-AGB stars. These type of objects represent a key piece of information for understanding the shaping of PNe. For the selected objects we have observational evidences of that the bipolar processes, responsible for the breaking of the spherical symmetry in PNe, have already reach a stage of development that make them detectable with arcsecond resolutions. We will observe their IR emission with several filters covering the whole operational range of ISOCAM and using a pixel field of view of 1.5". These observations will allow us to study the properties of the dust in these envelopes (temperature, distribution of the mass and of some dust spectral features: silicates, ice). We will also analyze the recent mass loss history of their central stars. We also expect to resolve the dust structures associated with the bipolarity of the object (a collimating disk, the interaction of the two winds, etc.), which will allow us to test the current theories for the shaping of PNe. Finally, the comparison of the dust properties derived from the ISOCAM observations with those for the neutral gas (obtained from other ongoing projects) will be of fundamental importance, expecially for the study of the late-AGB and post-AGB mass losses and of the chemical processes that occur during this post-AGB evolution.