PROBLEM TO BE SOLVED: To acquire information related to a depth which is a distance from an observation object of an insertion part distal end when observing a subject or acquiring images.SOLUTION: An endoscope apparatus 1 includes a detection point setting part 17 for acquiring two images, defining any point in one image as a base point, defining a projection point to which the base point projects on a straight line connecting the center of a scanning trajectory of one optical fiber 21, 22 in one image and the center of the scanning trajectory of the other optical fiber in the other image as a first detection point, and setting a point corresponding to the first detection point in the other image as a second detection point. On the basis of the circulating number of the spiral scanning trajectory of one optical fiber at the first detection point of one image and the circulating number of the spiral scanning trajectory of the other optical fiber at the second detection point of the other image, the depth H to the observation object of an insertion part 5 is computed.
