To reduce generation of abnormal noise between an upper support and a suspension tower.

The upper support 11 of a strut 10 is mounted on the suspension tower 20 by using each of bolts 30. In the suspension tower 20, a regular triangle shaped hole 20a is formed. In each corner part C1, C2 and C3 of the hole part 20a, each non-contact part which is not contact with an upper surface of the upper support 11 is formed. At the center outside of each side part L1, L2 and L3 of the hole part 20a, each bolt inserting hole 20b, 20c and 20d for inserting each bolt 30 is formed. When the upper support 11 is mounted on the suspension tower 20, each of the bolts 30, each of the bolt inserting holes 20b, 20c and 20d and each nut part 12b, 12c and 12d are coaxially arranged by using a tool 40.