The present invention facilitates the operation to mount the top of a shock absorbing member to be installed in the upper part of a side door, to a door constituent member without causing an increase in the number of parts. A door outer panel 2 has a top folded-back part F, where the top flange 10a of the shock absorbing member 10 is fitted in. A fold-back piece 21 is furnished with a notch 24, and a positioning projection 23 to suit the notch 24 is formed on the shock absorbing member 10. The bottom of the shock absorbing member 10 is fastened to an impact bar 5 crossing the side door 1 in the front-rear direction of the vehicle body using a fastener.