A modular Coriolis flowmeter includes: a measuring tube module, including a measuring tube for guiding the medium, an excitation magnet on a vibration exciter for exciting the measuring tube, and a sensor magnet on a vibration sensor for detecting a vibration of the measuring tube; a receiving module including a receptacle for receiving the measuring tube module, an excitation coil on the vibration exciter, a sensor coil on the vibration sensor, and a receiving module body, including a ferromagnetic material and an opening, wherein a coil holder for the excitation coil and/or sensor coil is disposed in the opening, the coil holder including a coil holder body including an electrically insulating material.