An objective is to employ medical images corresponding respectively to two different types of x-ray energy to generate a medical image that corresponds to an x-ray energy that an operator desires in a short amount of time and with high contrast and low noise. A medical image processing device according to the present embodiment comprises: an image storage unit which stores first and second medical images derived respectively from x-rays of first and second energies an estimation unit which estimates a proportion for either of a first substance or a second substance of the other substance thereof being present for each pixel, on the basis of an attenuation constant of the first substance corresponding to the first and second energies, an attenuation constant of the second substance corresponding to the first and second energies, and pixel values in the first and second medical images a composite ratio determination unit which determines a composite ratio of pixel values between the first and second medical images for each pixel on the basis of the probability of the presence of the first and second substances and each attenuation coefficient of the first and second substances relating to a target energy and a composite image generation unit which generates a composite image from the first and second medical images relating to the target energy, using the determined composite ratio.Lobjectif de la présente invention est demployer des images médicales correspondant respectivement à deux types différents dénergie de rayons X pour générer une image médicale qui correspond à une énergie de rayons X quun opérateur souhaite dans une courte période de temps et avec un contraste élevé et un bruit faible. Un dispositif de traitement dimage médicale selon le présent mode de réalisation comprend : une unité de stockage dimage qui stocke des première et seconde images médicales dérivées respectivement de rayons X de première et seconde énergies une unité destimation qui estime un
