PURPOSE: To improve general purpose usability of a spare tire antitheft means by forming its structure such that a box of a holding means is supported by a spare tire hanger further to make the box sinkable in a recessed part formed in a rim of a spare tire so as to fix the spare tire by tightening a nut to a bolt protrusively provided in this box.

CONSTITUTION: In a device holding a spare tire 4 by a holding means 11 to a spare tire hanger 3 rotatably supported in a horizontal direction to a rear part of a car body 1, the holding means 11 is supported by the hanger 3, further to provide a box 13 sunk into a recessed part 42 of a rim 41 of the tire 4. At least one the first bolt 19 is inserted from a side of the rim 41 to a through hole of the box 13, to screw a nut 20 from a side of the box 13 to this bolt. A plurality of the second bolts, protruded to a side of the rim, are protrusively provided in the box 13, to fix the tire 4 by screwing a nut to this second bolt. An opening 15 of the box 13 can be closed by a lid 25 locked by a lock device 29.