PURPOSE: To prevent flapping of a trunk lid and keep a suitable open angle of a trunk lid according to size of a baggage by fitting both upper and lower holding bodies between the rear wall of a body and a trunk lid simply and firmly, and adjusting the upper holding body to expand or contract against the lower holding body by a tightening means.

CONSTITUTION: For mounting a trunk lid holder 6 for an automobile on a body, in the open condition of a trunk lid 4, at first the projections 13 of a lower holding body 10 are positioned on the opening of a locking part 12, and a holder main body 8 is placed on the rear wall 3 of the body. Nextly, a hanging hook 22 on the lower end of an elastic cord 9 is inserted through the lower inserting hole of the lower holding body 10, and hung on a locking member 21 on the body side. Nextly, the cord 9 is elongated, and a hanging ring 24 on the upper end is hung on a locking member 23 on the lid side through the upper inserting hole of the upper holding body 11. Hereby, the trunk lid 4 is energizated in the closing direction by elastic force of the cord 9, and the holder main body 8 is surely held. Thereafter, considering size of a baggage in a trunk room, the upper body 11 is suitable expanded or contracted vertically against the lower body 10, and tightened on the position with screws.