Inference device, inference method, and inference program

An inference device (100) is provided with a quantization inference unit (110), a non-quantization inference unit (120), and a feature data extraction unit (130). The quantization inference unit (110) performs, by using inference data, one or more quantization calculations based on a machine learning method. The non-quantization inference unit (120) performs, by using the inference data, at least one of one or more non-quantization calculations corresponding to the one or more individual quantization calculations. When overflow occurs in at least one of the one or more quantization calculations, the feature data extraction unit (130) extracts quantization feature data corresponding to each quantization calculation in which overflow has occurred, and non-quantization feature data corresponding to a non-quantization calculation corresponding to each quantization calculation in which overflow has occurred.