To provide a method for installing a photovoltaic module which has a supporting member that is made of a member having excellent productivity, and thereby can remarkably improve its reliability in corrosion resistance over the whole part of itself.

When the photovoltaic module having a framework made of aluminum or aluminum alloy is installed in an architectural structure through the supporting member made of a steel material, the photovoltaic module makes a flow of rain water therefrom flow and drop on a surface of a cover member by covering one part of the supporting member with the cover member having at least surface made of aluminum or aluminum alloy. As for the cover member, molten Al plated sheet steel, dip braze Al plated sheet steel and the like are used.