We propose to survey the Hubble Deep Field (HDF) at 6.7 and 15 mu with CAM. This will be a natural extension of the work of the ELAIS team, which is carrying out a survey of 20 sq deg of sky at 15 and 90 mu, using 215 hours of ISO Open Time. The team now involves 19 European institutes and is supported by one of the 3 EC TMR Networks awarded in astronomy (some of the ELAIS institutes are involved in other bids to survey the HDF). We have been carrying out a detailed study of the HDF since its release and are preparing a paper for submission shortly on the nature of the faint galaxies detected in the HDF (Rowan-Robinson et al 1996). The key from the point of view of ISO is the very high proportion of very blue, star-forming galaxies in the sample. Over 80% of the galaxies have colours and morphologies consistent with being in the process of undergoing vigorous star formation and it is a reasonable expectation that a high proportion of them will have strong far infrared excesses. We have used our standard star-burst spectral energy distributions (Pearson and Rowan-Robinson 1996, MN in press) to predict the 6.7 and 15 mu fluxes from the HDF galaxies. We find that LW2 and LW3 are capable of detecting of order 50 HDF galaxies with S/N=5 in integrations of 2 hours per detector for each of the 3 WF fields. This is close to the confusion limit for CAM, so that longer integrations are unlikely to be worthwhile. The software we are already developing for analysis of the ELAIS data will be immediately suitable for this project and we have a strong team to carry out this data analysis at ICSTM, supported by the other teams of the consortium. Our expertise in the analysis of ISO survey data, coupled with the detailed work we have been carrying out on the HDF, ensures that high-quality data and science analysis products would be delivered to the community if this proposal were successful.