NOVELTY - The connection structure has a primary L-shaped metal fitting (25) whose vertical piece (25a) is contacted by horizontal bolts (29). The primary L-shaped metal fitting is attached on one side wall (16a) of an upper portion of a pile (16). A vertical piece (26a) of a secondary L-shaped metal fitting (26) is contacted by bolts. The secondary L-shaped metal fitting is attached to a pair of side wall (14a) of a lower portion of a support (14). The horizontal upper pieces (25b,26b) of primary and secondary L-shaped metal fittings are connected together by vertical bolt (30) and nuts (31).    USE - Leg portion connection structure of mount frame for solar cell panels installed in wide ground or in building.    ADVANTAGE - The implantation operation to underground of a pile can be facilitated, the implant pile can be maintained firmly in the earth, and a support can be stably supported in the ground. The height adjustment of each support suitable for the inclination-angle of the solar cell panel can be implemented by a construction site, and the height can be stably kept according to the connection structure using the bolt-nut of the primary L-shaped metal fitting and the secondary L-shaped metal fitting. The installation of a mount frame and adjustment of inclination can be performed simply and rapidly, and installation of the mount frame for solar cell panels can be achieved efficiently at low cost, without carrying out placement construction, such as a large scale concrete foundation etc.    DESCRIPTION OF DRAWING(S) - The drawing shows the schematic perspective view illustrating the connection structure of the leg portion.    Support (14)    Side wall of support (14a)    Pile (16)    Side wall of pile (16a)    Primary L-shaped metal fitting (25)    Vertical upper piece of primary L-shaped metal fitting (25a)    Horizontal upper piece of primary L-shaped metal fitting (25b)    Secondary L-shaped metal fitting (26)    Vertical upper piece of secondary L-shaped metal fitting (26a)    Horizontal upper piece of secondary L-shaped metal fitting (26b)    Horizontal bolts (29)    Vertical bolts (30)    Nuts (31)