A resist underlayer film-forming composition including: (A) component: an isopoly or heteropoly acid, or a salt thereof, or a combination thereof; and (B) component: polysiloxan, poly hafnium oxide or zirconium oxide, or a combination thereof, wherein an amount of the (A) component is 0.1 to 85% by mass of a total amount of the (A) component and the (B) component; and polysiloxan is a hydrolysis-condensation product of hydrolyzable silane of Formula (1): R1aR2bSi(R3)4−(a+b)  Formula (1) and a hydrolyzable silane whose (a+b) is 0 is contained in a proportion of 60 to 85 mol % of a total hydrolyzable silane in Formula (1); the poly hafnium oxide is a hydrolysis-condensation product of hydrolyzable hafnium of Formula (2): Hf(R4)4  Formula (2) and the zirconium oxide is a hydrolysis-condensation product of hydrolyzable zirconium of Formula (3) or Formula (4): Zr(R5)4  Formula (3) ZrO(R6)2  Formula (4) or a hydrolysis-condensation product of a combination thereof.