PURPOSE: To raise the accuracy of setting by a method in which a horizontal plate is fixed to the upside of a rectangular base material of a given thickness, a projecting part is set in parallel with the center of the horizontal plate, and column-fitting metals are continuously provided at an adequate interval.

CONSTITUTION: A strip footing panel P is made up of a rectangular base material 1, panel-column joints 2 and 3, floor beam-panel joints 4 and 5, and a flooring part 6 and fixed on a mat foundation B. The base material 1 is made up of a steel frame 10 consisting of upper and lower steel skeletons 4 and 5 and a vertical steel skeleton 14 and a concrete part 11, and the panel joint 2 is formed of the spline joint 20 of the projected part. The column joint 3 is formed on the upside of the horizontal plate 12a, and the floor beam joint 4 is provided on the side of the base material 1. The panels P are connected with the panel joint 5 and the flooring part 6 is made up of a female screw cylinder 32 fixed to the horizontal plate 13a and bolts 33. Strong strip foundation can thus be constructed.