A crusher-is disposed at a distal end of an operating boom of a construction vehicle. The crusher permits the breaking of a crushed mass of natural stone by means of a breaking force occurring between a stationary jaw body and a movable jaw body as the movable jaw body is closed toward the stationary jaw body. A flat auxiliary member is replaceably disposed on the stationary jaw body opposing the movable jaw body so as to break the crushed mass into smaller pieces. The distal end of the stationary jaw body projects longer than the distal end of the movable jaw body to facilitate the raking out of the crushed masses obtained in a blasting operation.