A telephoto lens system having a plurality of lenses toward a focal object is proposed. The system includes a first lens with a positive refractive power, a second lens with a negative refractive power, a third lens with a negative refractive power, a fourth lens with a negative refractive power, and a fifth lens with a positive refractive power. A refractor bending an optical axis is provided between the second lens and the third lens. The angle (A) between the optical axes of the second lens and the third lens satisfies 80°≤A≤86°. A barrel surrounding the first lens is provided by protruding more toward the focal object than the first lens. The inner diameter of the barrel is smaller than or equal to the effective diameter of the first lens, and a stop is arranged toward the focal object of the first lens.