A purpose of the application is to provide a semiconductor device production method capable of reducing complexity of production operations and keeping production costs low, and enhancing reliability, and a semiconductor device. One aspect of the invention provides a method of producing a semiconductor device, the method including a first bonding step of bonding a first electrode plate and a semiconductor device portion, and a second bonding step of bonding the semiconductor device portion and a second electrode plate. The method includes a sealing step of forming a sealed composite body by covering target surfaces of a composite body formed by the first bonding step with resin, the target surfaces being surfaces other than a second surface of the first electrode plate and the second surface of the semiconductor device portion. The second bonding step is performed after the sealing step.