An image sensing device comprises a pixel array, and a peripheral circuit, a column selecting circuit, and a readout, wherein each pixel includes a photodiode, a floating diffusion, a transfer PMOS transistor to the floating diffusion, an amplifier PMOS transistor, and a reset PMOS transistor, the amplifier PMOS transistor has a gate which is formed by an n-type conductive pattern, and is isolated by a first element isolation region and an n-type impurity region which covers at least a lower portion of the first element isolation region, and each PMOS transistor included in the column selecting circuit has a gate which is formed by a p-type conductive pattern and is isolated by a second element isolation region, and an n-type impurity concentration in a region adjacent to a lower portion of the second element isolation region is lower than that in the n-type impurity region.