To provide an eave soffit structure, which can cope with the change of the height of an eave soffit material caused by the change of the length of the projection of eaves from the skeleton of a building and by which the execution of works on a construction field is reduced, and a method for executing the eave soffit structure.

An eave-soffit substrate board is installed between the upper end section of a sheathing material and the skeleton, length in the vertical direction of the eave-soffit substrate board is set longer than the variation of the height of the eave soffit material caused by the change or projecting length from the skeleton of the eaves, and the eave soffit structure can cope with the change of the height of the eave soffit material corresponding to the change of projecting length from the skeleton of the eaves without adjusting the position of the mounting of the eave-soffit substrate board.