Authors developed a novel type of cable reel named “Unicorn Reel (UR)” for mobile robots working in hostile environments that utilize a cable for communications and power supply. Authors introduced a pipe-elected reel configuration for the UR to receive the cable from all directions, and a new type of level winder consisting of passively swing lever to lead the cable from the pipe to the reel. Although it is simple in mechanism, authors could show by the basic experiments that it realizes good level winding feature. Authors made the UR hermetic and introduced pressurized air to prevent contamination of the reel.