This endoscope apparatus includes an endoscope insertion unit, an imaging optical system, a measurement processing unit, a reliability determination unit, and a notification control unit. The imaging optical system is disposed at a distal end of the endoscope insertion unit. The measurement processing unit performs a measurement process by the principle of triangulation on the basis of an image corresponding to an optical image obtained via the imaging optical system, a first camera parameter including a first position, and a second camera parameter including a second position different from the first position. The reliability determination unit determines the reliability of the measurement process. The measurement process is based on a measurement point set in the image corresponding to the optical image obtained via the imaging optical system at the first position. The notification control unit sends a notification to prompt a user to perform an operation of moving the distal end in a direction from the second position toward the first position when the reliability determination unit determines that the reliability is low.
