In the diagnosis of peripheral nerve disorder such as carpal tunnel syndrome, the doctor and the scientific occupational therapist mainly narrow down the position of the lesion by function evaluation. The diagnosis has been decided by the evaluation of the electrophysiological nerve conduction characteristics. In addition to this, in recent years it has become possible to observe the median nerve as a tomogram using an ultrasound diagnostic apparatus, so it is possible to check the thickness and shape of the median nerve without cutting the wrist joint part. However, in order to objectively observe a tissue having a three-dimensional structure such as a median nerve, it is required to obtain not only tomographic images of the median nerve but also three-dimensional shape information. Therefore, in order to visualize the median nerve as the three-dimensional structure, we develop a device that mechanically manipulates an ultrasound probe, while operating an ultrasound probe, it takes photographs the nerve tomographic images as well as it extracts the nerve from the images. In this paper, we describe the development of a device that operates an ultrasound probe and extract the median nerve in an ultrasound images.