Provided are a separation type unit pixel for preventing sensitivity reduction to prevent a depletion area from decreasing and a method of driving the unit pixel. The separation type unit pixel for preventing sensitivity reduction includes: a substrate; a photodiode constructed with a junction of a P-type diffusion area and an N-type diffusion area which are formed under a surface of the substrate in a vertical direction; a gate electrode conductor which is disposed on an upper portion of the surface of the substrate to be adjacent to the N-type or P-type diffusion area; a floating diffusion area formed to be adjacent to another surface of the gate electrode conductor; and a sensitivity reduction preventing conductor disposed on an upper portion of the photodiode area to cover the photodiode area.