To easily inflate an air bag when required by providing needle holes which are invisible in a surface material for automobile to cover a part to store the air bag to store the air bag in an unnoticeable manner.

The pin-hole working is performed in a surface material 3 on which the printing ink and gloss regulator are coated on a three-layered body comprising a surface layer 4 made of polypropylene, a foamed layer 5 made of foamed polypropylene, and a barrier layer 6 by a needle of 1.2 mm in diameter with 4.5 mm in the longitudinal and transverse pin-hole intervals. The pinhole working is performed on the whole area of only the surface layer 4 made of polypropylene. The surface material 3 having the pinholes is heated to 180°C with a recessed die having a leather stripe pattern to provide the stripe pattern, the raw material for the base material is injection molded to the recessed die to integrate the surface material 3 with the base material 2. The needle holes in the surface material of a formed article are invisible.