To provide a spacer for mounting an imported wheel on a hub of a domestic car having a stud bolt, and a space for mounting a domestic wheel having a nut hole for a stud bolt on a hub of an imported car having no stud bolt.

The spacer has bolt insertion holes 5 in a circumferential surface of a substantially disk-shaped spacer body 4, which are holes to receive a plurality of stud bolts 3 erected on a hub 1 of a domestic car and have receiving seats of nuts 6 tightened to the bolts. Bolt screwing holes 7 to screw and tighten mounting bolts 10 to be inserted from holes 9 for mounting bolts formed in a circumference of a mounting part of an imported wheel 8 are formed in the circumferential surface of the spacer body 4 not interfered with the insertion holes 5.