A medical device and medical material using an aromatic biodegradable resin composition, which is not susceptible to decrease in strength and impact resistance during sterilization by ionizing radiation. Specifically disclosed are ionizing radiation sterilized medical device and medical material, which are characterized by containing a composition composed of an aromatic polyester-based biodegradable resin and a polylactic acid, with the polylactic acid being 25 to 70 wt% of the weight of the composition. The medical device and medical material are biodegradable, while having excellent strength and impact resistance.