A method for manufacturing a conductive polymer solid electrolytic capacitor comprising: a conductive polymer introduction step; and a solvent removal step, wherein: the conductive polymer introduction step comprises impregnating a porous material with a dispersion, the dispersion includes a conductive polymer dispersed in a non-aqueous solvent, the conductive polymer includes at least one of the structural units represented by the following formula and the following formula, in the formulas and, R 1 is an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alkylene oxide group having 1 to 12 carbon atoms and having 1 to 50 repeating units, a phenyl group optionally having a substituent, a heterocyclic group optionally having a substituent, or a condensed ring group optionally having a substituent, A - is an anion derived from a dopant and n is 2 or more and 300 or less, wherein 80 to 100 mass% of the dopant include a dopant having 1 or 2 anions in one dopant molecule; the conductive polymer has a volume average particle diameter D50 of 0.1 to 100 nm in the dispersion, measured by a photodynamic scattering method; the porous material includes an electrode material which is a sintered body of particles, and a dielectric covering a surface of the electrode material; and the solvent removal step comprises removing at least a part of the non-aqueous solvent and forming a solid electrolyte which covers the surface of the porous material. a conductive polymer introduction step; and a solvent removal step, wherein: the conductive polymer introduction step comprises impregnating a porous material with a dispersion, the dispersion includes a conductive polymer dispersed in a non-aqueous solvent, the conductive polymer includes at least one of the structural units represented by the following formula and the following formula, in the formulas and, R 1 is an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alkylene oxide group having 1 to 12 carbon atoms and having 1 to 50 repeating units, a phenyl group optionally having a substituent, a heterocyclic group optionally having a substituent, or a condensed ring group optionally having a substituent, A - is an anion derived from a dopant and n is 2 or more and 300 or less, wherein 80 to 100 mass% of the dopant include a dopant having 1 or 2 anions in one dopant molecule; the conductive polymer has a volume average particle diameter D50 of 0.1 to 100 nm in the dispersion, measured by a photodynamic scattering method; the porous material includes an electrode material which is a sintered body of particles, and a dielectric covering a surface of the electrode material; and the solvent removal step comprises removing at least a part of the non-aqueous solvent and forming a solid electrolyte which covers the surface of the porous material. the conductive polymer introduction step comprises impregnating a porous material with a dispersion, the dispersion includes a conductive polymer dispersed in a non-aqueous solvent, the conductive polymer includes at least one of the structural units represented by the following formula and the following formula, in the formulas and, R 1 is an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alkylene oxide group having 1 to 12 carbon atoms and having 1 to 50 repeating units, a phenyl group optionally having a substituent, a heterocyclic group optionally having a substituent, or a condensed ring group optionally having a substituent, A - is an anion derived from a dopant and n is 2 or more and 300 or less, wherein 80 to 100 mass% of the dopant include a dopant having 1 or 2 anions in one dopant molecule; the conductive polymer has a volume average particle diameter D50 of 0.1 to 100 nm in the dispersion, measured by a photodynamic scattering method; the porous material includes an electrode material which is a sintered body of particles, and a dielectric covering a surface of the electrode material; and the dispersion includes a conductive polymer dispersed in a non-aqueous solvent, the conductive polymer includes at least one of the structural units represented by the following formula and the following formula, in the formulas and, R 1 is an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alkylene oxide group having 1 to 12 carbon atoms and having 1 to 50 repeating units, a phenyl group optionally having a substituent, a heterocyclic group optionally having a substituent, or a condensed ring group optionally having a substituent, A - is an anion derived from a dopant and n is 2 or more and 300 or less, wherein 80 to 100 mass% of the dopant include a dopant having 1 or 2 anions in one dopant molecule; the conductive polymer has a volume average particle diameter D50 of 0.1 to 100 nm in the dispersion, measured by a photodynamic scattering method; the porous material includes an electrode material which is a sintered body of particles, and a dielectric covering a surface of the electrode material; and the solvent removal step comprises removing at least a part of the non-aqueous solvent and forming a solid electrolyte which covers the surface of the porous material.