To provide a fixture for mounting a photovoltaic power generating system on an installation surface such as a wall surface, which is light in weight, small in parts count, diverted from a solar battery module for an inclined roof or a flat roof of an ordinary house, thereby contributing to cost reduction and improved workability, and fit for the case of retrofitting of the solar battery module to an existing building, and to provide a method for mounting the system.

The fixture is for use in mounting the solar battery module on the target installation surface. A holding main body of the fixture has one or more holding projections and a shaft member having a solar battery module retaining member at the tip thereof. The retaining member is movable in an axial direction of the shaft member. Thus, by using the fixture thus formed, a single operator can easily temporarily fix and install the solar battery module on the installation surface, which leads to improved workability, reduction in parts count, and weight reduction of component members, to thereby curtail costs.