There is described a medical examination and/or treatment apparatus with an electromagnet for generating a magnetic field for navigating a medical instrument and an x-ray device having an x-ray source and an x-ray detector attached to a bracket for visual control during the navigation, with the x-ray source and the x-ray detector being arranged on the electromagnet embodied as a hollow cylinder, on the front ends of which are located two ring coils which are arranged in parallel, between which a number of saddle coils arranged in the peripheral direction are arranged, with the hollow cylinder being arranged on a bracket which can be moved about a number of axes.