A printed circuit board unit includes a printed circuit board and an electronic component. The electronic component is electrically connected to a predetermined position on the printed circuit board by means of soldering while being joined to the printed circuit board using an adhesive layer. The adhesive layer, disposed between the printed circuit board and the electronic component, partially includes a multilayer laminated region including a first reinforcement resin layer and a second reinforcement resin layer. The first reinforcement resin layer is disposed on a side of the printed circuit board, whereas the second reinforcement resin layer is disposed on a side of the electronic component. The second reinforcement resin layer has adhesive strength greater than that of the first reinforcement resin layer.