PURPOSE: To provide a cable processor connected to a self-propelled in-water inspection robot which is capable of swimming in water and simply and easily checking and inspecting the soundness of incore components such as components inside a core shroud in a reactor pressure vessel, components placed below the core support plate and incore component such as jetpumps without removing core support plate and upper grid plate.

CONSTITUTION: In a cable processor 15 for the cable 13 connected to a self-propelled in-water inspection robot 12 capable of swimming in water, a support column 17a capable of passing a narrow opening and arms 101a, 101b capable of folding in a shape capable of passing a narrow opening or containing in the support column are provided. To the support column 17a and the arms 101a, 101b, means 104a to 104d for guiding the cable 13 are provided.