An auto-focusing device of a camera includes a photographic lens having a focusing lens group guided along an optical axis, a stepping motor for moving the focusing lens group along the optical axis to bring an object into focus; and a controller for controlling the stepping motor to rotate stepwise when the depth of focus is smaller than a predetermined value and for controlling the stepping motor to rotate the rotor by even-numbered steps when the depth of focus of the photographic lens is greater than the predetermined value.
