Disclosed is an apparatus for measuring bio-information of a user. The apparatus includes an input device for receiving basic bio-information of the user, a first light source radiating a first light having a first wavelength on the surface of the skin, a second light source radiating a second light having a second wavelength on the surface of the skin, a third light source arranged so as to be placed in a more distant position from a photo detector than the first and the second light sources, said third light source radiating a third light having a third wavelength on the surface of the skin, the photo detector for detecting a first, second and third detection lights transmitted through the surface of the skin and converting said first, second and third detection light into electrical signals, said first, second and third detection light corresponding to said first, second and third wavelengths and a control unit for enabling the first, second and third light sources to be driven in a known order and for producing bio-information of the user on the basis of the inputted basic bio-information and intensities of the first, second and third detection lights.