a device and method for monitoring a high - pressure pump in a turbomachine fuel supply circuit by detecting opening of a pressurizing and shut - off valve mounted on an outlet side of a fuel flow regulating valve , by measuring rotational speed of the turbomachine corresponding to the opening of the pressurizing and cut - off valve , and by monitoring change in a value of the rotational speed to propose replacement of the high - pressure pump when the measure value rotational speed reaches a predetermined threshold .