PROBLEM TO BE SOLVED: To provide a creation method of a model animal, the model animal for cardiac visualization for use in development of heart disease treatment device and medical training, in which a case fatality rate during surgery and after surgery is low and a survival time can be extended.SOLUTION: A creation method of a model animal comprises: a step of peeling a pleura from the pericardium through an opening formed beside the xiphoid process; a step of stopping bleeding of an internal thoracic vein and an internal thoracic artery by ligating each ventral side of the internal thoracic vein and the internal thoracic artery after ligating the head side of the internal thoracic vein and the internal thoracic artery, respectively; and a step of resecting ribs from fifth rib to second rib while stopping bleeding of the costal intercostal artery and intercostal vein of each rib. The model animal is provided in which a portion of a chest wall is resected by the creation method and the heart beating in the b
