An image analysis apparatus includes a moving image input unit which accepts an input of a moving image of a subject irradiated with X-rays, a determination unit which analyzes the previous frame and current frame of the moving image, and determines based on the analysis result whether or not any of a change in relative position between an exposure field of the X-rays and an observation portion of the subject, a change in imaging condition of the moving image, and a change in observation portion of the subject is detected, and a feature amount setting unit which sets feature amounts extracted from the current frame in the current frame when the determination unit determines that any of the changes is detected, and sets feature amounts set in the previous frame in the current frame when the determination unit determines that no change is detected.