A guide assembly of a self-propelled type for an endoscope having an elongated tube for entry in a body cavity is provided. First and second self-propelled units are secured to a steering device provided in the elongated tube, arranged in an axial direction of the elongated tube, the second self-propelled unit receiving force for driving from an external drive source. A flexible connector connects the second self-propelled unit to the first self-propelled unit and transmits the force applied to the second self-propelled unit to the first self-propelled unit. Preferably, the connector includes at least two coil springs having diameters different from one another, and combined in such a multi layer form that winding directions thereof are opposite to one another. The force is torque in a rotational direction about an axis of the axial direction.
