To use a mask sheet whose environmental load is small.

The supporting body of the mask sheet 5 is constituted of a supporting body obtained by sticking a PET sheet 13 where an aluminum vacuum-deposited layer 15 is formed and a PET sheet 14 by laminating work. The surface of the supporting body on the PET sheet 13 side is coated with a white printing layer 17 and a decorative printing layer 18. The surface thereof on the PET sheet 14 side is coated with a heat seal layer 19 consisting of a hotmelt adhesive being an inorganic solvent in 15 μm thickness by a T-die extruding machine.