A treatment liquid composition for semiconductor production including: a quaternary ammonium hydroxide; and a first organic solvent dissolving the quaternary ammonium hydroxide, the first organic solvent being a water-soluble organic solvent having a plurality of hydroxy groups, wherein a water content in the composition is no more than 1.0 mass % on the basis of the total mass of the composition; contents of Na, Mg, Al, K, Ca, Ti, Cr, Mn, Fe, Ni, Cu, and Zn in the composition are each no more than 100 mass ppb on the basis of the total mass of the composition; and a content of Cl in the composition is no more than 100 mass ppb on the basis of the total mass of the composition.