A flexible flat micro-Fluxgate sensor with amorphous rectangular core, fabricated using a simple printing technique is presented. All materials were selected to facilitate the fabrication process and to achieve optimal sensor performance. The device’s response to an externally applied magnetic field has been studied. The linear measuring range of the sensor is approximately ±40 μT with a linearity error of <2% FS at 100 kHz excitation frequency, allowing the measurement of the terrestrial magnetic field. Experimental results demonstrate that the behaviour of the fabricated device corresponds to the behaviour of a Fluxgate sensor with high sensitivity.