An automatic focusing device in a camera comprises drive means for moving a picture-taking lens in the direction of the optic axis so that the picture-taking lens can be focused to an object from the shortest distance to infinity, detector means having photoelectric converter means and adapted to emit a focus position signal when the image formation plane of the object by the picture-taking lens is not coincident with an optimal focusing plane and to emit a focusing signal when the image formation plane is substantially coincident with the optimal focusing plane, a shutter release operating button displaceable between a first operating position and a second operating position and adapted, when displaced to the second operating position, to release the shutter of the camera, trigger means adapted to emit an operating signal when the shutter release operating button is displaced to the first operating position, and means for controlling the drive means such that the picture-taking lens is moved in response to application of the focus position signal and the operating signal, that said movement of the lens is stopped in response to application of the operating signal and the focusing signal and that after the stoppage of the lens, said movement becomes possible only in response to re-application of the operating signal.