A method of predicting a shape of a semiconductor device includes implementing a modeled semiconductor shape with respect to a designed semiconductor layout, extracting a plurality of samples by independently linearly combining process variables with respect to the modeled semiconductor shape; generating virtual spectrums with respect to ones of the extracted plurality of samples through optical analysis, indexing the virtual spectrums to produce indexed virtual spectrums, generating a shape prediction model by using the indexed virtual spectrums as an input and the modeled semiconductor shape as an output, and indexing a spectrum measured from a manufactured semiconductor device and inputting the spectrum to the shape prediction model to predict a shape of the manufactured semiconductor device.