PURPOSE: To meet a design reference for a wooden column base-buried foundation by a method in which specific fitting parts are fixed to underground concrete beams in grid-like trench under the ground, and a concrete layer of a downwardly facing bowl form is formed below the specific fitting parts.

CONSTITUTION: A grid-like trench 4 is formed of a grid-arranged broken cobble stone layer 1 and adjacent upheaved gravel layers 3 at a given depth below the ground's surface. In the trench 4, a concrete underground beam 2 is formed at a lower level than the upper end face of the layers 3, and a column base fitting part 6 having a fixing portion 61 on its lower end and a column base insertion space 63 and the joint 66 of brace S on its upper part is fixed to the upside of the beam 2. A concrete layer 5 is also formed over the periphery exclusive of the upper end of the part 6 and the upsides of the beam 2 and the layers 3, and an air vent (not illustrated) is formed in the layer 5. The wooden structure, therefore, can meet a structural type under a design standard even when sleeper, etc., is omitted.