An object of the present invention is to provide an extendable strut that can be easily attached and can construct a desired vinyl house by using a pillar whose height can be adjusted by expanding and contracting as a base of a pillar member of the vinyl house. An outer column (10), an inner column (20), and an elevating device are provided. The outer column (10) is provided at one end of the inner column (20), and the elevating device is attached between the inner column (20) and the outer column (10). 32 is mounted in the outer column 10 so as to be pivotable about a pivot, and the other end of the screw 32 is coupled to a coupling hole 351 penetrating the lever base 31, and when the screw 32 rotates, the outer column 10 is connected to the inner column 20. A telescopic column that can move up and down and gives a height adjustment function, thereby adjusting the lifting device even when the depth of the mounting hole at the installation position of the vinyl house does not match Thus, the height of each column can be adjusted to be the same. [Selection] Figure 2【課題】伸縮することにより高さを調整可能な柱をビニルハウスの柱部材のベースとすることで、取り付けやすくし且つ所望のビニルハウスを建設できる伸縮可能な支柱を提供する。【解決手段】外側柱１０、内側柱２０及び昇降装置を備え、外側柱１０が内側柱２０の一端に套設され、昇降装置が内側柱２０と外側柱１０の内部の間に取り付けられ、スクリュ３２により枢軸に回動可能に外側柱１０内に取り付けられ、スクリュ３２の他端がレバーベース３１を貫通する結合孔３５１に結合され、スクリュ３２が回転するとき、外側柱１０が内側柱２０に対して上下移動可能になり、高さ調整機能を付与する、伸縮可能な支柱であり、それによって、ビニルハウスの設置位置にある取付孔の深さが一致しない場合においても、昇降装置を調整することにより各支柱の高さを一致にさせるように調整できる。【選択図】図２
