PURPOSE: To easily form an interior finishing base having a deep drawn part, to prevent reinforcing paper from tearing in the forming of the deep drawn part, to prevent a contamination on a surface of a skin material and an occurrence of an abnormal sound without generating gas permeability in the interior finishing base, and to improve bonding strength of the reinforcing paper.

CONSTITUTION: Reinforcing paper 13 impregnated with a thermosetting resin is laminated on at least one surface of a felt layer 12. The reinforcing paper 13 impregnated with the thermosetting resin is made of crape paper unidirectionally shrunk at random. The crepe paper is laminated on the felt layer 12 through an adhesive 15. This is press molded into a required shape by a thermal press mold. In this manner, an interior finishing base 11 is formed.