An image sensor includes a first photodiode group, a second photodiode group, a first transfer transistor group, a second transfer transistor group, a floating diffusion region of a substrate in which electric charges generated in the first photodiode group are stored, and a power supply node for applying a power supply voltage to the second photodiode group. A barrier voltage is applied to at least one transfer transistor of the second transfer transistor group. The power supply voltage allows electric charges, generated in the second photodiode group, to migrate to the power supply node, and the barrier voltage forms a potential barrier between the second photodiode group and the floating diffusion region.