Method for mounting a guide apparatus of a large hydraulic machine having a vertical axis of rotation, wherein the axes of the guide blades extend vertically, wherein the method comprises the following steps: assembling an assembly at least comprising the upper guide wheel ring or the turbine cover and all the guide blades of the guide apparatus, wherein the assembly does not take place in the machine shaft and the guide blades are mounted in a suspended manner, lowering the guide blades to mutually different heights within the assembly such that the lowered guide blades can be displaced upwardly, installing the lower guide wheel ring in the machine shaft, and installing the assembly in the machine shaft by continuous lowering, wherein the guide blades present in the assembly are successively inserted into the openings provided in the lower guide wheel ring.