An optical image stabilizer includes a motion sensor configured to sense a movement of a camera, and a controller configured to move a lens module based on the movement of the camera. The optical image stabilizer enters a standby mode based on an OIS turn-off command being received from a host, in response to the camera being turned off or a camera function being executed in a background during a stage in which an optical image stabilization (OIS) operation is performed. A portion of the functional blocks of the optical image stabilizer is turned off when a lens control is not performed even when the optical image stabilizer is being operated, thereby decreasing power consumption. Functional blocks as small as possible may be operated when the optical image stabilizer is not operated to decrease power consumption in a smartphone or a camera in which the optical image stabilizer is embedded.