On a substrate surface at a position facing an outer circumference end portion of a semiconductor element, a recessed section wherein a sealing adhesive resin is partially arranged is formed. Thus, while suppressing expansion of an arrangement region of a fillet portion (a portion spreading toward bottom) of the sealing adhesive resin, the inclination angle is increased. A stress load generated atthe periphery of the semiconductor element due to thermal expansion differences and thermal shrinkage differences between members due to heating process and cooling process for mounting is reduced, and internal breakage of a semiconductor element mounting structure is eliminated.