An object is to provide a technique capable of fixing a cover to a container body without using a dedicated fixation mechanism and fixation member. A semiconductor device includes: a container body having a space with an opening; a semiconductor element disposed in the space in the container body; a sealing member disposed in the space in the container body to cover the semiconductor element; and a cover covering the opening of the container body, wherein a convex portion protruding into the space is provided on the cover, and the cover is fixed to the container body only by embedding at least a tip portion of the convex portion in the sealing member which has been cured.