Clusters of galaxies in the mid-infrared

We describe the results of observations of galaxy clusters conducted with ISOCAM on-board the Infrared Space Observatory. Our research is aimed at understanding the processes driving galaxy evolution in dense environments, free from the bias of dust extinction. The results reveal quite a complex picture: the star-formation activity of cluster galaxies does not show a simple evolution with redshift, but also depends on the dynamical status and evolutionary history of the clusters.