A camera system for monitoring the inside of a body, which is easily used and can be installed during a short period of time, is suggested. A drawing auxiliary tool (7) having a wire structure guides a camera unit (11) and a camera side cable (12) in which one end part is connected to the camera unit (11) from the outside of the body toward the inside of the body via a first hole provided on a body wall, and draws out the other end part of the camera side cable (12) from the inside of the body toward the outside of the body via a second hole provided on the body wall.
