An anchor bolt which is surely fixed to, for example, a rock wall and is easy to carry and store is provided. The anchor bolt according to the present invention has expandable devices (5) which are disposed at three locations of a rod (3). When the anchor bolt is inserted into a bore (2), a free end of an abutment part (16) of the expandable device (5) abuts an inner peripheral surface (26) of the bore (2), and expandable members (13) are held in the bore (2). In this state, when a taper member (12) is moved toward a base end of the anchor bolt along with the rod (3), an inclined surface (15) of the taper member (12) surface-contacts an inner surface (19) of the abutment part (16), and an outer peripheral surface (20) of the abutment part (16) is pressed against an inner peripheral surface 26 of the bore (2).