A nuclear magnetic resonance tomograph or an imaging magnetic resonance apparatus (1) has a magnet (3) which is isolated in terms of vibration from a surrounding structure, in particular a building floor (15), by an isolation system (17). The isolation system (17) has an actively controlled isolation module (23) which is preferably designed to damp non-acoustic vibrations, in particular vibrations with a frequency of less than 50 Hz. According to a preferred embodiment, moreover, a passive isolation module (21) with a vibration-damping material (D) is present. A particularly high degree of isolation of the magnet (3) from the surrounding structure can be achieved with the aid of the isolation system (17).