To provide an inner focus type lens that is small and has a high imaging performance, the lens having a vibration-proof lens light in weight and less in an amount of movement for image blur correction.

This inner focus type lens comprises, in order from the object side, a first lens group G₁₁ of positive refractive power, a second lens group G₁₂ of negative refractive power, and a third lens group G₁₃ of positive refractive power. The first lens group G₁₁ comprises a negative lens L₁₁₄ having the function of a vibration-proof lens, and an aperture stop STP. By including the vibration-proof lens in the first lens group G₁₁, the imaging magnification of the vibration-proof lens itself can be increased. Accordingly, an amount of movement of the vibration-proof lens during vibration-proof correction can be decreased. Since the vibration-proof lens is composed of a single negative lens L₁₁₄, the weight of the movable lens can be made light.