PURPOSE: To enable a hoist to move to any position in a two-dimensional directions including the outside of the crane body by running the crane body along a rail, expanding and contracting a beam in the direction perpendicular to the rail, and putting the hoist to run along the beam.

CONSTITUTION: A crane device for constructing a building is equipped with a rail 12 fixed to a frame 2 which is supported in the uppermost part of a building being constructed, a crane body 6 to run under the frame 2 along the rail 12, a beam 8 installed in the crane body 6 expanding and contracting in the direction perpendicular to the rail 12, and a hoist 17 which runs along the beam 8. Thereby each piece of construction materials hung up from the ground can be transported to any two-dimensional position within the scope of the works, which leads to enhancement of the effectiveness of execution of works with this construction method.