| abstract |
An adhesive film (50) of the present invention includes a base material layer (10), an adhesive resin layer (A) provided on a first surface (10A) side of the base material layer (10), and an adhesive resin layer (B) provided on a second surface (10B) side of the base material layer (10) and of which an adhesive force is reduced by an external stimulus. When a mass of the adhesive film (50) after heating and drying at 130°C for 30 minutes is defined as W<sub>1</sub> and the mass of the adhesive film (50) after the heated and dried adhesive film (50) is left for 24 hours at 25°C under an atmosphere of 50% RH to absorb water is defined as W<sub>2</sub>, an average water absorption rate indicated by 100 x (W<sub>2</sub>-W<sub>1</sub>)/W<sub>1</sub> is 0.90% by mass or less. |