An ultrasound imaging apparatus comprising: an ultrasound probe including a transducer module including an ultrasound transducer array, a driving device configured to rotate the transducer module, and a position sensor configured to output a signal based on a change in rotation of the transducer module; and a controller, CHARACTERISED BY a magnet configured to rotate as a result of rotation of the transducer module, wherein the position sensor is configured to output one of a first signal and a second signal based on a change in magnetic flux density according to rotation of the magnet, and IN THAT the controller is configured to determine a first time for which the first signal is output as the transducer module rotates in a first direction, control the driving device to switch rotating direction of the transduce module from the first direction to a second direction at a first switching time point at which an output signal is switched from the first signal to the second signal, control the driving device to switch the rotating direction of the transducer module one or more times during a time corresponding to the first time with respect to a second switching time point at which the output signal is switched from the second signal to the first signal after the first switching time point, determine a second time for which the first signal is output after the second switching time point, and determine a backlash value based on a difference value between the first time and the second time, wherein the position sensor switches the output signal from the second signal to the first signal when the magnetic flux density reaches a first magnetic flux density, as the magnet moves toward the position sensor, and switches the output signal from the first signal to the second signal when the magnetic flux density reaches a second magnetic flux density as the magnet moves away from the position sensor. an ultrasound probe including a transducer module including an ultrasound transducer array, a driving device configured to rotate the transducer module, and a position sensor configured to output a signal based on a change in rotation of the transducer module; and a controller, CHARACTERISED BY a magnet configured to rotate as a result of rotation of the transducer module, wherein the position sensor is configured to output one of a first signal and a second signal based on a change in magnetic flux density according to rotation of the magnet, and IN THAT the controller is configured to determine a first time for which the first signal is output as the transducer module rotates in a first direction, control the driving device to switch rotating direction of the transduce module from the first direction to a second direction at a first switching time point at which an output signal is switched from the first signal to the second signal, control the driving device to switch the rotating direction of the transducer module one or more times during a time corresponding to the first time with respect to a second switching time point at which the output signal is switched from the second signal to the first signal after the first switching time point, determine a second time for which the first signal is output after the second switching time point, and determine a backlash value based on a difference value between the first time and the second time, wherein the position sensor switches the output signal from the second signal to the first signal when the magnetic flux density reaches a first magnetic flux density, as the magnet moves toward the position sensor, and switches the output signal from the first signal to the second signal when the magnetic flux density reaches a second magnetic flux density as the magnet moves away from the position sensor.