PURPOSE: To increase an amount of energy absoption without entailing any drop in appearance and quality as well as without narrowing an interval between ribs.

CONSTITUTION: An interval between an opening part 22A of a pocket 22 and an armrest 24 of a door trim 12 is set to be an energy absorbing part 26, and each rib 28 integrally formed in this droor trim 12 in a grid-like manner in both vertical and longitudinal directions and each hollow boss 30 formed in an intersecting point between the ribs 28 both are formed in the backside of this energy absorbing part 26. Each of these bosses 30 is formed into a cylindrical form, and each end of the ribs 28 is connected to an outer circumferential part. In addition, each height of the bosses 30 is equal to that of the ribs 28, and a top face of each boss 30 is flush with that of the rib 28.