Machine for machining large parts of the type that comprises a parallel kinematics machining device that moves freely in the X, Y and Z Cartesian axes, characterized in that the said device is mounted on a platform which moves in the Z axis and is in turn mounted on a bridge that slides along corresponding guides in the X and Y axes. The invention put forward affords the significant advantage of combining the high machining precision and speed of the parallel kinematics machine with the fact that the machine can access large work areas owing to the support platform which is mounted on the bridge.