A method is provided for characterizing the amplitude of play in an electromechanical actuator comprising an electric motor, a movable element, an upstream sensor, a downstream sensor, and a force sensor. The method includes steps of measuring the position of the motor, the position of the movable element and the load applied to the movable element using the three sensors. On the basis of a computer model of the actuator and of the measurements, a value of the amount of mechanical play is estimated using a state observer considering the play to be a state component. The amplitude of the play is determined from a set of values of the dynamic variable obtained in the preceding step at various times.