To realize an air-conditioning duct for automobile having high shock absorbability.

This air-conditioning duct 1 for automobile is made of thermoplastic resin molded integrally by blow molding and is provided with one wall 2 and the other wall 3 facing each other at an interval in a direction applied with shock (an arrow direction) and a shock absorbing rib 6 buried with a planar reinforcing core material 7 projecting from the one wall 2 toward the other wall 3. The shock absorbing rib 6 is provided along the longitudinal direction and a tip of the shock absorbing rib 6 and the other wall 3 are integrated via a welding part. The one wall 2 is inclined to the other wall 3, one side wall 4 and the other side wall 5 provided continuously on both side end parts of the one wall 2 and the other wall 3 face each other in substantially parallel. Flow passages 9a and 9b are formed on both sides of the shock absorbing rib 6.