To provide a fixing bolt and a lower end part close adhesion type crime prevention device for a fixing nut capable of making exposure of the fixing bolt and the fixing nut to the outside difficult when fixing an object to be fixed on an object by the fixing bolt and the fixing nut.

A clearance is formed by a space member 10 among a head part 2a of the fixing bolt 2 and surfaces of a washer 2b and a number plate 1. The space member 10 is composed of a cylindrical spacer part 11, a bottom plate part 12, and a bottom plate raising part 13. A crowning member 20 is crowned on the head part 2a of the fixing bolt 2 and the washer 2b. A locking claw 23 for bolt is formed in a lower end part of a side wall part 22 of the crowning member 20. A circular projecting part is formed in a lower end part of an internal wall face of a peripheral wall member 30 having a hollow cylindrical shape. The circular projecting part presses the side wall part 22 of the crowning member 20, and locking claws 24, 25 for peripheral wall member are engaged with the circular projecting part.