There is no such thing as "the" Max Planck Institute. In fact, the Max Planck Society operates a number of research institutions in Germany as well as abroad. These Max Planck Institutes are independent and autonomous in the selection and conduct of their research pursuits. To this end, they have their own, internally managed budgets, which can be supplemented by third party project funds. The quality of the research carried out at the institutes must meet the Max Planck Society's excellence criteria. To ensure that this is the case, the institutes' research activities undergo regular quality reviews.
The Max Planck Institutes carry out basic research in the life sciences, natural sciences and the social and human sciences. It is thus almost impossible to allocate an individual institute to one single research field: conversely, it can be the case that different Max Planck Institutes carry out research in the same subject.