PROBLEM TO BE SOLVED: To provide an OCT apparatus capable of changing a display range with a simple configuration without deteriorating reliability of a measurement value.SOLUTION: An OCT apparatus includes an interference optical system, a resolution changing part, and a calibration value calculation part. The interference optical system splits a light from a light source into a measurement light and a reference light, irradiates the measurement light onto an object to be measured, and detects an interference light between the return light from the object to be measured and the reference light. The resolution changing part changes the resolution in an optical axis direction of the interference optical system. The calibration value calculation part acquires a calibration value of the resolution based on the result of detection of the interference light in a state that the resolution is changed by the resolution changing part.SELECTED DRAWING: Figure 3【課題】測定値の信頼性を低下させることなく、簡素な構成で表示範囲の変更が可能なＯＣＴ装置を提供する。【解決手段】ＯＣＴ装置は、干渉光学系と、分解能変更部と、較正値算出部とを含む。干渉光学系は、光源からの光を測定光と参照光とに分割し、測定光を被測定物体に照射し、被測定物体からの戻り光と参照光との干渉光を検出する。分解能変更部は、干渉光学系の光軸方向の分解能を変更する。較正値算出部は、分解能変更部により分解能が変更された状態における干渉光の検出結果に基づいて、分解能の較正値を求める。【選択図】図３
