The present invention relates to a photobioreactor for mass culture of microalgae. The present invention provides a photobioreactor for mass culture of microalgae, comprising: a culture container comprising external walls which comprise an optical filter zone capable of selective penetration or blocking of a part of wavelength or region from sunlight and/or a heat conversion zone for selectively absorbing a part of wavelength or region from sunlight to convert the same into heat, and a reaction chamber which is three-dimensionally formed so as to accommodate microalgae and is an inner space restricted by the external walls; and a coupling means for connecting a floating means which is connected to the culture container or the culture container to the bottom of the water or a structure on the water, thereby locating the culture container near the surface of the water for the exposure of the culture container to sunlight.