The endoscope system includes an image signal acquisition processing unit and an image generation unit that acquire a first still image and a video or a second still image before and after acquisition of the first still image based on an image signal obtained by imaging an observation target using an image sensor, an association unit that associates the first still image with the video or associates the first still image with the second still image, and a storage unit that stores the first still image and the video associated with each other or stores the first still image and the second still image associated with each other.