To provide an imaging apparatus equipped with a variable focal distance lens whose variable power driving load is small, while realizing high variable power rate/high performance/compactness.

A zoom lens system TL has a 1st lens group GR1 having positive power, a 2nd lens group GR2 having negative power, a 3rd lens group GR3 having positive power, a 4th lens group GR4 having positive power and a 5th lens group GR5 having positive power in order from an object side, and the focusing is performed by moving the 5th lens group GR5. The 5th lens group GR5 has at least one positive lens Lp5 and at least one negative lens Lm5, in this order from the object side. It satisfies the conditional expressions: Np5<Nm5 (Np5: the refractive index of the positive lens in the 5th lens group, and Nm5: the refractive index of the negative lens in the 5th lens group), and νp5<νm5 (νp5: the Abbe number of the positive lens in the 5th lens group, and νm5: the Abbe number of the negative lens in the 5th lens group).