In a video coding device, a generation unit generates the prediction error signal from an input image, a transformation unit transforms the prediction error signal depending on a color space selected from among the plurality of color spaces, an adaptive chroma quantization offset derivation unit derives an adaptive chroma quantization offset, which is a parameter for adjusting a quantization parameter of a chroma component, for each of the plurality of color spaces, a quantization unit generates a quantization coefficient image based on the prediction error signal or the transformed prediction error signal by the transformation means, and an inverse quantization unit inverse-quantizes the quantization coefficient image by using the adaptive chroma quantization offset for the selected color space.