NOVELTY - The structure (M) has a main-portion (1) which consists of truncated-cone-shaped cylinder. A flange (3) is protruded outward from the opening edge (2) by the large diameter side of main-portion. An anchor object holding portion (7) is formed with an opening (11a) which is enclosed by the opening edge (4) by the small diameter side of main-portion and is traversed. The anchor object holding portion is provided with long-dimension stretcher portion (7A,7B) which has a shaft hole (6) penetrated to anchor object.    USE - Permanent structure of concrete foundation for installing solar cell array of solar energy power generation system.    ADVANTAGE - The anchor object holding portion is provided with opening enclosed by small diameter side opening edge and long-dimension stretcher portion which has a shaft hole penetrated to anchor object, so that the stable positioning state is acquired and the concrete foundation is constructed easily. The permanent structure of concrete foundation which responds also to installation of large sized structure is provided. Since the surface of a concrete foundation is protected by the permanent structure, the countermeasure against salt damage of concrete is achieved. Since the permanent structure has a main portion with a truncated-cone-shaped cylinder, the main-portion does not transform or swell easily. Since the truncated-cone-shaped main-portion stacks up several components, the reduction of storage area is achieved. The outer peripheral side cut-off-wall has flange protrudes ranging from the outer peripheral portion to a perimeter of flange wall, so that the water generated from the ready mixed concrete poured in main-portion is prevented from flowing out.    DESCRIPTION OF DRAWING(S) - The drawing shows the perspective views of permanent structure of concrete foundation from upper and bottom face sides.    Main-portion (1)    Opening edge by large diameter side (2)    Flange (3)    Opening edge by small diameter side (4)    Shaft hole (6)    Anchor object holding portion (7)    Long-dimension stretcher portion (7A,7B)    Opening (11a)    Permanent structure of concrete foundation (M)