Semiconductor device and method of manufacturing the same

A semiconductor device includes a wiring substrate, a semiconductor chip whose connection terminal is connected to the wiring substrate, an underfill resin formed from a clearance between the wiring substrate and the semiconductor chip to a periphery area of the semiconductor chip, wherein the underfill resin in the periphery area is formed at a same height as an upper surface of the semiconductor chip, an auxiliary member fixed on the semiconductor chip by an adhesive layer, and including a protruding portion which protrudes to an outside from the semiconductor chip, and the protruding portion arranged at least on the underfill resin via the adhesive layer, and a sealing resin sealing the underfill resin and at least side faces of the auxiliary member, wherein respective coefficients of thermal expansion of the auxiliary member and the adhesive layer are larger than a coefficient of thermal expansion of the semiconductor chip.