An airframe panel for aircraft having stringers and ribs which enables reduction of the workload of the shimming operation includes a plurality of stringers provided on the inner surface of a lower skin along the spanwise direction of a wing, and a plurality of ribs provided along the chordwise direction of the wing. In a part of the panel in which a rib is provided, a flat support surface connects the two adjacent stringers. In another part of the panel in which no rib is provided, a stepped surface connects the two adjacent stringers where the stepped surface includes a thin-walled groove, and thick-walled bases to be connected to the stringers located at both sides of the groove.