In one embodiment, a semiconductor device includes a first insulator. The device further includes a first pad provided in the first insulator, and including first and second layers provided on lateral and lower faces of the first insulator in order. The device further includes a second insulator provided on the first insulator. The device further includes a second pad provided on the first pad in the second insulator, and including third and fourth layers provided on lateral and upper faces of the second insulator in order. The device further includes a first portion provided between an upper face of the first pad and a lower face of the second insulator or between a lower face of the second pad and an upper face of the first insulator, and including a metal element same as a metal element included in the first layer or the third layer.