This is addressed to provide a zoom lens which has a good optical performance for imaging device having a large number of pixels even with its simple construction, and which can also be small and thin in structure, and an imaging apparatus using the zoom lens. A zoom lens 1 is composed by arranging, in the following order from an object side, a first lens group GR1 having a weak refractive power, a second lens group GR2 having a negative refractive power, a third lens group GR3 having a positive refractive power, and a fourth lens group GR4 having a positive refractive power, and is configured to perform zooming by moving the second lens group and the third lens group. The first lens group is composed by arranging, in the order from an object side, a single lens G1 having a a negative refractive power, a prism G1 for folding an optical path, and a single lens G3 having a a positive refractive power. The second lens group is composed of one single lens G4 having a negative refractive power, and satisfies the following conditional formula (1): t2/fw