Abstract: To calculate the properties of a resin composition in a short time and with high accuracy, a resin property value prediction apparatus includes an acquisition unit acquiring spectral data obtained by measuring a resin composition by a spectroscopic sensor in a process of performing a resin polymerization reaction in a batch type reaction tank and a calculation unit, using a learned model learned with spectral data obtained by measuring the resin composition in advance and a resin property value as training data, calculating the resin property value of the resin composition having the spectral data acquired by the acquisition unit.