An example embodiment provides an image sensor including: a pixel array including a first floating diffusion and a second floating diffusion, the first floating diffusion and the second floating diffusion configured to store charges generated by a first phase detecting pixel and a second phase detecting pixel adjacent to each other in a first direction and covered with one micro lens, and the pixel array is configured to output a first signal based on a charge that is generated by the first phase detecting pixel to be accumulated in the first floating diffusion and the second floating diffusion; and a row driver configured to apply a boosting control signal to the second floating diffusion to transfer charges stored in the second floating diffusion to the first floating diffusion, after the pixel array outputs the first signal.