A white light source system comprising at least one white light source comprising: a light emitting diode having a light emission peak wavelength in a range of 350 or more and 420 nm or less; and a phosphor layer including four or more types of phosphors having different peak wavelengths, and resin, wherein the phosphors for constituting the phosphor layer consists of a combination of at least: a blue light emitting phosphor that is excited by a primary light emitted from the light emitting diode thereby to emit a secondary light; a green light emitting phosphor that is excited by absorbing the primary light emitted from the light emitting diode thereby to emit a secondary light, and by absorbing the secondary light emitted from the blue light emitting phosphor thereby to emit tertiary light; a yellow light emitting phosphor that is excited by absorbing the primary light emitted from the light emitting diode thereby to emit a secondary light, and by absorbing the secondary light emitted from the blue light emitting phosphor thereby to emit tertiary light, and by absorbing the secondary or tertiary light emitted from the green light emitting phosphor thereby to emit tertiary or quaternary light, and a red light emitting phosphor that is excited by absorbing the primary light emitted from the light emitting diode, thereby to emit a secondary light, and by absorbing the secondary light emitted from the blue light emitting phosphor thereby to emit a tertiary light, and by absorbing the secondary or tertiary light emitted from the green light emitting phosphor thereby to emit a tertiary or quaternary light respectively, and by absorbing the secondary, tertiary or quaternary light emitted from the yellow light emitting phosphor thereby to emit a tertiary, quaternary or quinary light respectively; in a visible light region of 380 to 780 nm the white light source satisfies a relational equation of: − 0.2 ≤ P λ × V λ / P λ max 1 × V λ max 1 − B λ × V λ / B λ max 2 × V λ max 2 ≤ + 0.2, assuming that: a light emission spectrum of the white light source is P(λ); a light emission spectrum of black-body radiation having a same color temperature as that of the white light source is B(λ); a spectrum of a spectral luminous efficiency is V(λ); a wavelength at which P(λ) × V (λ) becomes largest is λmax1; and a wavelength at which B(λ) × V(λ) becomes largest is λmax2, and wherein an amount of chromaticity change on CIE chromaticity diagram from a time of initial lighting up of the white light source to a time after the white light source is continuously lighted up for 6000 hours is less than 0.010. a blue light emitting phosphor that is excited by a primary light emitted from the light emitting diode thereby to emit a secondary light; a green light emitting phosphor that is excited by absorbing the primary light emitted from the light emitting diode thereby to emit a secondary light, and by absorbing the secondary light emitted from the blue light emitting phosphor thereby to emit tertiary light; a yellow light emitting phosphor that is excited by absorbing the primary light emitted from the light emitting diode thereby to emit a secondary light, and by absorbing the secondary light emitted from the blue light emitting phosphor thereby to emit tertiary light, and by absorbing the secondary or tertiary light emitted from the green light emitting phosphor thereby to emit tertiary or quaternary light, and a red light emitting phosphor that is excited by absorbing the primary light emitted from the light emitting diode, thereby to emit a secondary light, and by absorbing the secondary light emitted from the blue light emitting phosphor thereby to emit a tertiary light, and by absorbing the secondary or tertiary light emitted from the green light emitting phosphor thereby to emit a tertiary or quaternary light respectively, and by absorbing the secondary, tertiary or quaternary light emitted from the yellow light emitting phosphor thereby to emit a tertiary, quaternary or quinary light respectively; in a visible light region of 380 to 780 nm the white light source satisfies a relational equation of: − 0.2 ≤ P λ × V λ / P λ max 1 × V λ max 1 − B λ × V λ / B λ max 2 × V λ max 2 ≤ + 0.2, assuming that: a light emission spectrum of the white light source is P(λ); a light emission spectrum of black-body radiation having a same color temperature as that of the white light source is B(λ); a spectrum of a spectral luminous efficiency is V(λ); a wavelength at which P(λ) × V (λ) becomes largest is λmax1; and a wavelength at which B(λ) × V(λ) becomes largest is λmax2, and wherein an amount of chromaticity change on CIE chromaticity diagram from a time of initial lighting up of the white light source to a time after the white light source is continuously lighted up for 6000 hours is less than 0.010.