A scalar magnetometer includes a sensor element, a circuit carrier, a pump radiation source, a radiation receiver and evaluation means. The pump radiation source emits pump radiation. The sensor element preferably includes one or more NV centers in diamond as paramagnetic centers. This paramagnetic center emits fluorescence radiation when irradiated with pump radiation. The radiation receiver converts a intensity signal of the fluorescence radiation into a receiver output signal. The evaluation means detects and/or stores and/or transmits the value of the receiver output signal. The material of the circuit carrier is preferably transparent for the pump radiation in the radiation path between pump radiation source and sensor element and transparent for the fluorescence radiation in the radiation path between sensor element and radiation receiver. The components sensor element, pump radiation source, radiation receiver and evaluation means are preferably mechanically attached to the circuit carrier.