This platform provides access to a hydraulic machine via a suction tube. This hydraulic machine belongs to an installation for converting hydraulic energy into mechanical or electrical energy, or reciprocally. The platform includes a load-bearing element designed to slide along a longitudinal axis in order to enter an opening in the suction tube, said load-bearing element having an extremity that is designed to be immobilized in the suction tube and floor elements that are placed on the load-bearing element. At least some of the floor elements are articulated with the load-bearing element about axes substantially parallel to the longitudinal axis, while these floor elements can be rotated about these axes between a folded configuration and a deployed configuration and define at least a portion of a floor of the platform.