To achieve high mounting performance and high connection reliability in a semiconductor device by inhibiting warp due to a thermal expansion difference between a semiconductor element and a package substrate on which the semiconductor element is mounted.

A semiconductor device comprises: a semiconductor chip 1 connected on a substrate 4 via bumps 2; and a mold resin 3 provided around the semiconductor chip 1. By providing the mold resin 3 so as to satisfy a relationship represented as B>√2×A where A represents a distance from the semiconductor chip 1 to an edge of the mold resin 3 at from a corner of the semiconductor chip to in the vicinity of a corner of the substrate 4 and B represents a distance from the semiconductor chip 1 to an edge of the mold resin 3 in the vicinity of the center of a side of the substrate 4, warp of the semiconductor device can be easily inhibited with ensuring compact size, a thin thickness and reliability.