The invention aims to provide an optical system, aiming at realizing light weight and miniaturization of the whole optical system with an anti-shake group and have excellent imaging performance from infinity to microspur at the same time. The optical system includes: a first movement group moving along an optical axis direction at the time of focusing from an object at infinity to a short-distance object; a second movement group provided on an image side of the first movement group and moving to an object side by an amount of movement different from an amount of movement of the first movement group at the time of focusing from the object at infinity to the short-distance object; and an anti-shake group is arranged in the movement group containing the first movement group and the second movement group, and satisfies the following conditional expression (1): m1/m2<1.0...(1), wherein m1 is the amount of movement when the first movement group is from the infinity focusing state to the microspur focusing state, and m2 is the amount of movement when the second movement group is from the infinity focusing state to the microspur focusing state. Furthermore, about the amount of movement, a negative symbol is applied to the movement to the object side and a positive symbol is applied to the movement to the imaging side.