Flexible serpentine robots have high potential in the exploration of narrow spaces inside debris. To use these robots in actual search and rescue missions, they should not only have sufficient mobility but also exhibit various characteristics, such as information-gathering ability, operability, and durability. However, only a few robots have been developed focused on operability and durability. Therefore, this paper presents a flexible serpentine robot that realizes mobility, operability, and durability; further, it is capable of gathering information. The robot was evaluated in field experiments and feedback was obtained from rescue workers. In particular, we improved the mobility of a conventional Active Scope Camera (ASC) by installing a developed active air jet nozzle on the head. The thrust from the nozzle enables the ASC to move over a step of 22 cm height and quickly changes the head direction (580 mm in 0.4 s). In addition, a high operability is ensured by compacting the system components using an air cylinder. The entire robot system can be carried and operated by 2 people and the time for setup is approximately 3 min. The field experiments in a simulated disaster site showed that the developed ASC was able to explore a wider rubble environment in a shorter time than a conventional ASC. In addition, we confirmed that the system enables three operators to search for and locate a hidden object inside an unknown debris environment. Furthermore, 14 members of a rescue party operated the robot system and evaluated the system through a survey. The survey reveals which situations the proposed system was able to work properly in, which revealed the aspects in which the robot can be improved.