A semiconductor device comprising: a semiconductor substrate that has a first surface and a second surface opposite to each other and in which a through hole to extend from the first surface to the second surface is formed; a first wiring that is provided on the first surface and has a portion located above a first opening of the through hole on the first surface side; an insulating layer that is provided on an inner surface of the through hole and the second surface and is continuous through a second opening of the through hole on the second surface side; and a second wiring that is provided on a surface of the insulating layer and is electrically connected to the first wiring in an opening of the insulating layer on the first surface side, wherein the surface of the insulating layer includes: a tapered first region that reaches the first opening inside the through hole and enlarges from the first surface to the second surface, a tapered second region that reaches the second opening inside the through hole and enlarges from the first surface to the second surface, a third region that faces the second surface outside the through hole, a fourth region that is curved to continuously connects the first region and the second region, and a fifth region that is curved to continuously connect the second region and the third region, and wherein an average inclination angle of the second region from the first surface is smaller than an average inclination angle of the first region from the first surface and is smaller than an average inclination angle of the inner surface of the through hole from the first surface. a semiconductor substrate that has a first surface and a second surface opposite to each other and in which a through hole to extend from the first surface to the second surface is formed; a first wiring that is provided on the first surface and has a portion located above a first opening of the through hole on the first surface side; an insulating layer that is provided on an inner surface of the through hole and the second surface and is continuous through a second opening of the through hole on the second surface side; and a second wiring that is provided on a surface of the insulating layer and is electrically connected to the first wiring in an opening of the insulating layer on the first surface side, wherein the surface of the insulating layer includes: a tapered first region that reaches the first opening inside the through hole and enlarges from the first surface to the second surface, a tapered second region that reaches the second opening inside the through hole and enlarges from the first surface to the second surface, a third region that faces the second surface outside the through hole, a fourth region that is curved to continuously connects the first region and the second region, and a fifth region that is curved to continuously connect the second region and the third region, and wherein an average inclination angle of the second region from the first surface is smaller than an average inclination angle of the first region from the first surface and is smaller than an average inclination angle of the inner surface of the through hole from the first surface. a tapered first region that reaches the first opening inside the through hole and enlarges from the first surface to the second surface, a tapered second region that reaches the second opening inside the through hole and enlarges from the first surface to the second surface, a third region that faces the second surface outside the through hole, a fourth region that is curved to continuously connects the first region and the second region, and a fifth region that is curved to continuously connect the second region and the third region, and wherein an average inclination angle of the second region from the first surface is smaller than an average inclination angle of the first region from the first surface and is smaller than an average inclination angle of the inner surface of the through hole from the first surface.