Abstract: The present invention relates to an arrangement for affixing an expandable packer 22, 32 in a hole 30, wherein the arrangement includes a piston-and-cylinder device 11, 12 with which the piston can be caused to move in the cylinder with the aid of a pressurized medium. Expansion of the packer is effected with the aid of the movement of the piston 11, by transferring the force generated by piston movement to an expandable part 24, 34 of the packer 22, 32 so that said part will expand. Expansion of the packer results in the packer being firmly affixed in the hole by means of friction. The arrangement also includes an elongate main body 1 that has a through-penetrating aperture extending in the longitudinal direction of the body. The main body 1 has a front end 3, which faces inwardly of the hole when fastening the packer and towards the packer.