A pipe-inspecting apparatus having a self-propelled unit. The self-propelled unit comprises an elastic tube which has forward and rear ends, and into which a fluid is supplied and from which the fluid is discharged, a restriction member mounted on the elastic tube, for restricting an axial expansion of the elastic tube, a bias member for biasing the elastic tube in the axial direction thereof, first and second holding members coupled to the ends of the elastic tube, respectively, for holding the ends of the elastic tube to the inner periphery of a pipe being inspected, while the fluid is being supplied into the holding members, and releasing the ends of the elastic tube from the inner periphery of the pipe, while the fluid is being discharged from the holding members. An observation device is coupled to the self-propelled unit. A display device is connected to the observation device, for displaying the image scanned by the observation device. A fluid control device is connected to the elastic tube, and to the first and second holding members.