A device for repairing a crack in a wall includes an injection nozzle that has a nozzle part, and an adsorption disk fixed to a supporting shaft in which a suction passage for sucking air is formed and can be adsorbed to a wall surface by sucking air through the suction passage, and can be detached from the wall surface by releasing the suction, an arm having a front end part and a rear end part in the axial direction, and is supported by the supporting shaft in the midpoint of the axial direction through the first universal joint and supports an inflow pipe of the injection nozzle in the front end part through a second universal joint, and a plurality of contact members attached to the rear end part of the arm, the front end thereof contacting the wall surface, and receives the moment load generated in the arm.