A device for calibrating and testing echotomographic equipment comprises an electric motor, a pair screw—female screw, wherein the screw is connected to an outlet shaft of the motor and the female screw is mobile with respect to a supporting plane, so as to transform a rotary motion of the motor shaft into a linear motion, a piston connected to the female screw and linearly mobile, coherently to the female screw, a membrane stressed by the piston, means apt to allow propagating ultrasound waves towards/from said membrane.