French social sciences can rely on very instructive research, especially with regard to ethnographical investigations and qualitative analysis. However, some other issues remain disregarded, such as the situations of other European countries, or the relationships between prisons and the political field. This article invites to shed light on these two points. First, a few elements are given in order to sketch the German penal profile, with its own historical and geographical, legal and sociological features – it draws up by the way a state of research. Then, stressing the deep analogies and the common stakes that bring the German case near other ones in Europe, it aims at questioning the classical legal conception and recall the structural conditions that connect prisons with the whole social machinery. Insofar as imprisonment is neither just the result of a legal process nor a simple instrumental political device, this approach leads to emphasize the ambiguous relationships between prisons and the State.