[PROBLEMS] To provide a thermal insulation sheet for forced cultivation that can be easily installed and managed with a low material cost, and can be easily ventilated as a management in the installation and management of a thermal insulation tunnel necessary for the enhanced cultivation. SOLUTION: By adding a cushioning material for packing under the polyethylene thermal insulation sheet with the convex surface facing the thermal insulation sheet, an air layer is secured between the thermal insulation sheet and the cushioning material to improve thermal insulation, and this combination Only small tunnels using a single-layer structure, which conventionally required at least two large and small tunnels to be stacked, have been simplified and reduced in cost. [Selection] Figure 2【課題】促成栽培に必要な保温用トンネルの設置及び管理において、資材費が低コストで設置作業が容易、且つ管理として行う換気作業を容易に行える促成栽培用保温シートを提供する。【解決手段】ポリエチレン保温シートの下に梱包用緩衝材を凸面を保温シート側にして追加することで、保温シートと緩衝材の間に空気の層を確保して保温性を向上し、この組み合わせ一層構造を用いた小さなトンネルのみで、従来少なくとも大小二つのトンネルを重ねる必要があったものを簡便化、低コスト化した。【選択図】図２
