A step of preparing data of (1) material properties of a first part and so on and data of (2) an amount of solar radiation passing through the translucent member to reach a measuring device having a shape imitating a human body part, an amount of solar radiation to the structure, an amount of convection heat transfer in the structure, an amount of radiation heat transfer in the structure, humidity in the structure and/or a thermo-regulating function of the measuring device, and calculating at least one of the amount of heat loss from the surface of the measuring device, the temperature of the measuring device and/or the wettedness at the surface of the measuring device based on at least one in each of data (1) and (2), and a step (b) of calculating a thermal comfort index of the measuring device by using a result of the above calculation, are presented, whereby the thermal comfort of a structure is evaluated without using a laboratory equipment.