A semiconductor device may include a channel including an oxide semiconductor layer in a through hole; a first electrode in a first side of the through hole, the first electrode connected to a first side of the channel; a second electrode in a second side of the through hole and connected to a second side of the channel; and an insulating layer having a groove in which the second electrode is accommodated. The insulating layer includes first and second insulating films. The groove extends in a thickness direction. At least a part of the groove has a depth where at least a part of the groove penetrates through the first insulating film and reaches the second insulating film. The second electrode includes a stack of a metal film and a conductive film. The metal film is in contact with at least an inner bottom surface of the groove.