An anti-shake apparatus of a photographing apparatus includes a signal processor. A fixed unit slidably supports, in perpendicular first and second directions, a movable unit having an imaging device or a hand-shake correcting lens. The movable unit or fixed unit has a magnetic-field change detector which has a horizontal magnetic-field change-detecting element for detecting a first location and a vertical magnetic-field change-detecting element for detecting a second location. Another of the movable unit and the fixed unit has a position-detecting magnet unit which faces the magnetic-field change detector. The signal processor outputs a first detected-position signal and a second detected-position signal. The controller calculates the first location for the first detected-position signal and the second location for the second detected-position signal. The controller maximizes a width between minimum and maximum values of the first detected-position signal and between minimum and maximum values of the second detected-position signal.