The bending structural body comprises: an inner cylinder that is formed from a first inner coil part and a first outer coil part, and in which wound parts corresponding to the first inner coil part are respectively fitted to pitches between adjacent wound parts of the first outer coil part; an outer cylinder that covers at least some of the outer circumference of the inner cylinder with a space therebetween, that is formed from a second inner coil part and a second outer coil part, and in which wound parts corresponding to the second inner coil part are respectively fitted to pitches between adjacent wound parts of the second outer coil part; and drive wires and guide wires that are guided and axially inserted into the space between the inner cylinder and the outer cylinder.