The present invention relates to technology to implement a technique of managing light intensity by each wavelength band for a light apparatus at a low price, whereby the light intensity is suitable for plant growth. In the present invention, cheaper LED blue-chips are incorporated instead of more expensive LED red-chips which are conventionally incorporated in plant factories, which let the production cost of lighting apparatus for plant factories reduced. By applying red-series, green-series and yellow-series phosphors onto the LED blue-chips, light intensity by wavelength band of lighting apparatuses may meet target conditions which are favorable to plant growth. Further, work environment may be improved by reducing eyestrain due to red light-source, and growth efficiency of plants may be enhanced by improving wavelength characteristics of lighting apparatuses.