Various embodiments provide a device for measuring the flow of fluid inside a tube moved by a peristaltic pump is provided with: a detection electrode arrangement coupled to the tube to detect an electrostatic charge variation originated by the mechanical action of the peristaltic pump on the tube; a signal processing stage, electrically coupled to the detection electrode arrangement to generate an electrical charge variation signal; and a processing unit, coupled to the signal processing stage to receive and process in the frequency domain the electrical charge variation signal to obtain information on the flow of a fluid that flows through the tube based on the analysis of frequency characteristics of the electrical charge variation signal.