The present invention provides a semiconductor device exhibiting an improved reliability of a bump coupling section. A semiconductor device is provided, which comprises: an interconnect layer; a stress-relaxing layer, covering the interconnect layer and provided with an opening exposing at least a portion of the interconnect layer; a post, covering the opening and provided so as to overlap with the stress-relaxing layer disposed around the opening; and a resin layer, provided around the post to cover the stress-relaxing layer, wherein a value of 2A/C is within a range of from 0.1 to 0.5, wherein C is a diameter of the post and 2A is a width of an overlapping region of the stress-relaxing layer with the post.