Semiconductor device

A semiconductor device including at least two layers of interlayer-insulator-films stacked above a substrate and at least partially formed by a low-relative-dielectric-constant-film having a relative-dielectric-constant of 3.4 or less respectively, a plurality of wirings provided at least one within each of the interlayer-insulator-film and at least partially located within the low-relative-dielectric-constant-films, a plurality of plugs provided at least one within each of the interlayer-insulator-film and connected to a lower part of the wirings, and a plurality of reinforcement members provided at least one within each of the interlayer-insulator-film with being separated from the wirings at a predetermined interval, electrically cut from the wirings and the plugs, and at least partially located within the low-relative-dielectric-constant-films, and wherein, the interlayer-insulator-films, the wirings, the plugs, and the reinforcement members satisfy a predetermined relation for each of the interlayer-insulator-film.