A hole inspection unit, comprising - a hole inspection device having a bar-shaped probe, wherein the bar-shaped probe is adapted to be inserted into a hole to be inspected of an object in a central axis direction of the hole, for inspecting the hole, - a feeding device of the hole inspection device, the feeding device comprising: - an attaching jig for attaching the hole inspection device to the feeding device; - a movement mechanism that is coupled to the attaching jig and adapted to linearly reciprocate the hole inspection device together with the attaching jig; and - a positioning jig that is coupled to the movement mechanism and comprises a bushing adapted to slidably fit a positioning hole of a jig attached to the object so that the central axis of the positioning hole lies on the same straight line as the central axis of the hole, wherein the positioning jig is adapted to position the movement mechanism to the object, so that a moving direction of the attaching jig and the hole inspection device is made parallel to the central axis direction of the hole by positioning the movement mechanism and the length direction of the bar-shaped probe is on a straight line, passing through the inside of the bushing parallel to the central axis of the bushing in order to feed out the bar-shaped probe on the central axis of the hole. - a hole inspection device having a bar-shaped probe, wherein the bar-shaped probe is adapted to be inserted into a hole to be inspected of an object in a central axis direction of the hole, for inspecting the hole, - a feeding device of the hole inspection device, the feeding device comprising: - an attaching jig for attaching the hole inspection device to the feeding device; - a movement mechanism that is coupled to the attaching jig and adapted to linearly reciprocate the hole inspection device together with the attaching jig; and - a positioning jig that is coupled to the movement mechanism and comprises a bushing adapted to slidably fit a positioning hole of a jig attached to the object so that the central axis of the positioning hole lies on the same straight line as the central axis of the hole, wherein the positioning jig is adapted to position the movement mechanism to the object, so that a moving direction of the attaching jig and the hole inspection device is made parallel to the central axis direction of the hole by positioning the movement mechanism and the length direction of the bar-shaped probe is on a straight line, passing through the inside of the bushing parallel to the central axis of the bushing in order to feed out the bar-shaped probe on the central axis of the hole. - an attaching jig for attaching the hole inspection device to the feeding device; - a movement mechanism that is coupled to the attaching jig and adapted to linearly reciprocate the hole inspection device together with the attaching jig; and - a positioning jig that is coupled to the movement mechanism and comprises a bushing adapted to slidably fit a positioning hole of a jig attached to the object so that the central axis of the positioning hole lies on the same straight line as the central axis of the hole, wherein the positioning jig is adapted to position the movement mechanism to the object, so that a moving direction of the attaching jig and the hole inspection device is made parallel to the central axis direction of the hole by positioning the movement mechanism and the length direction of the bar-shaped probe is on a straight line, passing through the inside of the bushing parallel to the central axis of the bushing in order to feed out the bar-shaped probe on the central axis of the hole.