PURPOSE: To improve measurement accuracy by adding a conduit to a sensor support and supplying liquid to which temperature is already controlled to the conduit from a liquid temperature adjusting conveyance device.

CONSTITUTION: The sensor support 2 is located on the horizontal surface 1b of the body 1 to be measured so that noncontact displacement sensors 3a and 3b face the vertical surface 1a of the body 1 to be measured, and then put in a thermostatic chamber 5 together. Further, the conduit 4 and a sensor cable 6 are connected to the liquid temperature adjusting conveyance device 7 and a displacement display device 8 outside the thermostatic chamber 5 respectively. Then the temperature in the thermostatic chamber 5 is varied and set successively and the displacement of the vertical surface 1a at each temperature is detected by the sensors 3a and 3b. Their detection signals are sent to the display part 8 through the cable 6, converted, and displayed and recorded as the displacement. This data is plotted to know the tilt quantity of the vertical surface 1a to the horizontal surface 1b. Here, the liquid to which temperature is adjusted is sent to the support 2 from the device 7 through the conduit 4, so the support 2 is held at constant temperature and the sensors 3a and 3b are prevented from having detection errors.