A vertical transformer comprising a core provided with a middle leg installing a first and a second coils, a side leg, a first connection part connecting an end of the middle leg and that of the side leg, and a second connection part connecting the other end of the middle leg and that of the side leg, a first bobbin provided with a first hollow cylinder where at least either the first or the second coil is wound, and a core on-board face connected to an end of the first hollow cylinder, and an adhesive hardened part connecting a connection side face, and the core on-board face, and formed by hardening an adhesion, wherein the core on-board face is provided with a positioning part positioning the connection side face, and a positioning projection, is formed on both sides of the first connection part.