1. An endoscope apparatus comprising: a detector configured to detect a movement of an organ that moves a subject and output a detection signal; an image pickup portion configured to pick up an image of the subject and output a plurality of picked-up images; and a freeze processing portion configured to calculate a movement evaluation value evaluated according to the detection signal of the detector for at least some of the plurality of picked-up images, and determine a still image from the plurality of picked-up images based on the evaluated movement evaluation value.