With a view to provide a probe able to suppress bending of a cable with a mechanical scan, the probe comprises a transducer for interconversion between an ultrasonic wave and an electrical signal, a shell for holding the transducer, a case for accommodating the shell, a motor for moving the shell pivotally about a pivot shaft with respect to the case, a guide bar provided in the shell so as to extend in parallel with the pivot shaft, and coaxial cables extending from the transducer to the guide bar, wound round the guide bar and then extending out form the shell.