PROBLEM TO BE SOLVED: To provide a method for manufacturing a light transmission film, capable of sufficiently curing a heat ray absorption part without generating ultraviolet ray damage.SOLUTION: A light control film 10 is manufactured by a method of preparing a shaping film 3 having a plurality of shaping parts R slenderly depressed in a thickness direction Y and arranged in an in-plane direction X and charging a shaping part 5 with a composition including at least an ultraviolet curable resin and an infrared absorption material to form a heat ray absorption part 4. In the shaping part R, when a height of the shaping part R in the thickness direction Y is Ta, a pitch of the shaping part R in the in-plane direction X is P' and a base width of the shaping part R is W2', a numerical aperture Ro[(P'-W2')/P'] of the shaping part R is 0.2 or more and 0.9 or less, and an aspect ratio Ra[Ta/W2'] of the shaping part R satisfies a relationship of 0.72{(Ro/(1-Ro)}&le；Ra&le；0.58e. Ultraviolet irradiation for curing the composition for heat ray absorption part formation is performed at 1100-2800 mJ/cm.【課題】紫外線ダメージを生じさせることなく、熱線吸収部を十分に硬化させることができる光透過フィルムの製造方法を提供する。【解決手段】厚さ方向Ｙに細長く凹んだ賦形部Ｒが面内方向Ｘに複数配列されている賦形フィルム３を準備し、その賦形部５に、紫外線硬化性樹脂と赤外線吸収材料とを少なくとも有する組成物を充填して熱線吸収部４を形成する方法で光制御フィルム１０を製造する。このとき、賦形部Ｒは、厚さ方向Ｙでの賦形部Ｒの高さをＴａ、面内方向Ｘでの賦形部ＲのピッチをＰ’、賦形部Ｒの底辺幅をＷ２’としたとき、賦形部Ｒの開口率Ｒｏ［（Ｐ’－Ｗ２’）／Ｐ’］が０．２以上０．９以下であり、賦形部Ｒのアスペクト比Ｒａ［Ｔａ／Ｗ２’］が０．７２｛（Ｒｏ／（１－Ｒｏ）｝≦Ｒａ≦０．５８ｅ（３．４Ｒｏ）の関係を満たし、熱線吸収部形成用組成物を硬化するための紫外線照射を１１００～２８００ｍＪ／ｃｍ２で行う。【選択図】図３
