This paper proposes a method for detecting known objects in 3D environments and estimating their positions with multiple pan-tilt-zoom cameras. Our search method, Dynamic Active Search, reduces the number of camera operations by predicting the existence of a target in wide angles, zooming-in a promising area, and confirming the target. Even when many reference images taken under various object views and various scales need to be searched for, Dynamic Active Search can detect the object efficiently. With multiple cameras, object detection and object localization become more efficient. Experiments show that Dynamic Active Search with four cameras is 2.5 times faster and 2 times more accurate than with a single camera.