Consists of long containing a fiber reinforced synthetic resin, and a frame made from the arched portion and the main inflection portion, the cross-sectional shape of the main body portion and the curved portion polarization are different, the present invention, the main body portion tunnel cultivation of crops for frame, characterized in that the characteristic ratio and (Rm) the rigidity of the curved portion of the polarization and (Rf) rigidity of [Rm / Rf] is 2.0 to 4.0, and the ceiling portion, polarized song This is a method of manufacturing a frame having a cross section of a three-layer structure that forms an arch section, a soil buried portion and erected portion, and provides a tunnel cultivation frame of fiber-reinforced synthetic resin capable of forming a tunnel of the inverted U-shaped to.本発明は、繊維強化合成樹脂を含む長尺物からなり、偏曲部と主体部分から構成されるアーチ状フレームであって、該偏曲部と該主体部分の断面形状が異なり、該主体部分の剛性(Rm)と該偏曲部の剛性(Rf)との比〔Rm/Rf〕が2.0~4.0であること特徴とする農作物のトンネル栽培用フレーム、及び天井部、偏曲部、立設部及び土中埋設部でアーチを形成する三層構造の断面を有するフレームの製造方法であり、逆U字状のトンネルを形成できる繊維強化合成樹脂製のトンネル栽培用フレームを提供する。
