PURPOSE: To carry out extension and repair work at a site without disassembly work requiring much time, eliminate the necessity of a large scale lifting device and perform precise aligning work in relation to proper lift raising by applying a device to raise the lift of a crane to a container crane in particular.

CONSTITUTION: A raising device with lifting beam which can at least move upward keeping itself horizontal inward of the pier stud 110 of a crane K is arranged, and the lifting beam and the pier stud 110 are engaged with each other, and the pier stud 110 is separated at a position below this engagement portion, and then, with the lifting beam moved up, the body section of the crane K is raised, and a raising pier stud 110A is made to intervene at the raising portion of the pier stud 110 of the crane K.