Although the fish ladders for low drop structures, called groudsels, generally work relatively successfully, those for use in a sabo dams can not necessarily be easily built because those fish ladders for sabo dams are too high. It is practically impossible to build such fish ladders that work effectively after sedimentation starts in sabo dams before the sabo dams are filled with sediment. In this report, is proposed a new fish ladder for sabo dams that work effectively even before sedimentation starts afterward as well. It is a built-in terraced fish ladder. This fish ladder has windows on both of its side walls. The key to the success of this new fish ladder lies in whether or not an appropriate slope is selected. The flow in this new fish ladder was examined using hydraulic test models with and without sediment. The idea would seem promising, although no field examination has yet been carried out on those built-in terraced fish ladders in sabo dams where fish actually freely sail.