A measurement target (10) having a measurement target section and a reference gauge (20E, 20F) having a known reference gauge length (Dr) that is shorter than the length (Dt) of the measurement target section are placed in parallel in an inside of a temperature-controlled chamber (30). Relative measurement sections (M1, M2, M3) are allocated to the measurement target section, each having a length corresponding to the reference gauge length (Dr) and each being shifted by a predetermined shift amount (Dd). At first and second interior temperatures of the temperature-controlled chamber (30), first (Dt11, Dt21, Dt31) and second (Dt12, Dt22, Dt32) relative measurements of the length are performed for each measurement section (M1, M2, M3) with reference to the reference gauge (20E, 20F). A CTE of the measurement target section is calculated based on the CTEs of the relative measurement sections.
