A solid electrolytic capacitor element that includes a porous body, a dielectric layer on a surface of the porous body, and a solid electrolyte layer on a surface of the dielectric layer. The porous body is made from a sintered body of a Ti-alloy-containing grain having a Ti—Zr—X multicomponent alloy on a surface thereof, where X is at least one valve metal element selected from Si, Hf, Y, Al, Mo, W, Ta, Nb, and V, and a composition of the Ti—Zr—X multicomponent alloy is Ti: 50 atm % to 80 atm %, Zr: 8 atm % to 32 atm %, and X: 1 atm % to 20 atm %.