A pressure-sensitive adhesive sheet (62) which is provided with a sheet-shaped substrate (70) and a rubber-based pressure -sensitive adhesive layer (82) formed on at least one surface of the sheet-shaped substrate (70). In the substrate (70), at least the surface in the area to which the pressure-sensitive adhesive layer (82) is to be applied is formed from a resin material which comprises a polyolefin and polylactic acid as the main components and which has a biobased content of 35% or higher but below 100%.