1. A projection device projecting an image, comprising: a detection unit configured to detect a specific object; a projection unit configured to project a first projection image; a drive unit configured to change a direction of the projection unit so as to change a projection position of the first projection image; a controller configured to control the drive unit such that the first projection image is projected while following the motion of the specific object detected by the detection unit; and a communication unit configured to receive information of a second projection image projected by another projection device, wherein the controller acquires information relating to a position of the second projection image through the communication unit, and controls a projection method of the first projection image based on the positions of the first projection image and the second projection image such that the first projection image and the second projection image are not overlapped with each other when they are projected.