To prevent dispersion in construction depending on workers in a support device for mounting an on-roof installation object.

A roof tile 1 used for installing the on-roof installation object on a tiled roof surface if necessary is provided with a positioning mark 14 formed on the tile surface in a manufacturing step to open a hole used in installing the on-roof installation object on the roof tile. The boring position of the roof tile is thereby clear to eliminate dispersion in construction, and furthermore a solar panel mounting work can be easily carried out without choosing a favorable time after tiling. The positioning mark is formed in recessed shape or projecting shape to prevent an edge of a drill or the like from slipping on the tile surface during boring work, thereby improving work efficiency. Further, since a tile rear face facing the positioning mark in a wall thickness direction is thinned, the amount of boring work can be reduced, which leads to the life extension of the edge of the drill or the like.