To conduct maintenance such as cleaning, inspection, etc., easily by forming a broken section to an intermediate section in the vertical direction of a leader and installing a split gutter to the broken section.

The leader for inspection is formed of the leader 1, to which a broken section A is formed, and a detachable split gutter 2. The leader 1 is fixed onto a building T by a fixture 3 at that time. The broken section A is formed to an intermediate section in the vertical direction of the leader 1, and the split gutter 2 is mounted detachably on the broken section A. A packing 4 is fixed at the upper end of the split gutter 2. On the other hand, a supporting ring 5 is set up onto an inner circumferential surface in a section upper than the lower end of the split gutter 2. The inside diameter of the split gutter 2 is made larger than the outside diameter of the leader 1, and the inside diameter of the packing 4 is formed in a diameter fast stuck on the outside diameter of the leader 1. The gutter 2 is removed, and the space of the broken section A is utilized at the time of maintenance. The gutter 2 is lifted to the upper section of the leader 1 for removal, and the lower end of the gutter 2 is detached from the broken section A, and extracted from the leader 1, and taken off in a single operation type. Accordingly, operation can be conducted safely, surely and efficiently.