An anti-shake apparatus comprises a movable-unit, a fixed-unit, a signal-processor, and a controller. The movable-unit has an imaging-device and is movable in first-and second-directions, supported by the fixed-unit. The fixed-unit has a horizontal-hall-element for detecting a first-location, and a vertical-hall-element for detecting a second-location. The signal-processor outputs a first-signal specifying the first-location, from output signals of the horizontal-hall-element, to a first A/D-converter of the controller, and outputs a second-signal specifying the second-location, from output signals of the vertical-hall-element, to a second A/D-converter of the controller. The controller calculates the first-location in an A/D-converting-operation for the first-signal, and the second-location in an A/D-converting-operation for the second-signal. An optimized-horizontal-current-value is calculated in an initial-adjustment-operation for adjusting a detecting-resolution in the A/D-converting-operation for the first-signal, by changing the current-value flowing through the horizontal-hall-element. Current having the optimized-horizontal-current-value, flows through the horizontal-hall-element when detecting the position of the movable unit.