Solid electrolytic capacitor

A capacitor element includes a positive electrode body made of valve metal, a dielectric oxide layer on the positive electrode body, a solid electrolytic layer made of conductive polymer on the dielectric oxide layer, and a negative electrode layer on the solid electrolytic layer. A solid electrolytic capacitor includes the capacitor element, a package made of insulating resin covering the capacitor element, a base electrode provided at an edge surface of the package and made of non-valve metal coupled with the positive electrode body, a diffusion layer for connecting the positive electrode body to the base electrode, an external electrode on the base electrode, and an external electrode connected to the negative electrode layer. The solid electrolytic capacitor reduces the number of components and processes to reduce its cost and to have a small size, and has a small equivalent series resistance and a small equivalent series inductance.