The agricultural greenhouse of the invention and the plant cultivation method using the same can cultivate plants economically and efficiently with less energy per crop yield, as it is provided with a CO2 supply means, a heat-ray shielding means, and a dehumidification and cooling means, the heat-ray shielding means is formed of using a heat-ray reflecting film, and plural through holes are formed in the heat-ray shielding means. The heat-ray reflecting film structure can cultivate plants by the agricultural greenhouse utilizing sunlight economically and efficiently as it has a structure that narrow band-shaped tapes obtained by cutting a multi-layer laminated film made by laminating at least two kinds of resin layers with different refractive indices alternately and having an average transmittance at 80% or more for visible light and an average reflectance at 70% or more for heat-ray is woven or knitted as a warp or a weft.