Controller of radiation therapy equipment and method for measuring position of specific part

A specific site location measuring method according to the present invention, includes: calculating matching degrees based on a plurality of transmission images imaged by use of radiation transmitting through a specimen and a template set; selecting a template transmission image from the plurality of transmission images based on the matching degrees; adding a new template generated based on the template transmission image, to the template set; imaging a location measurement transmission image by use of radiation transmitting through the specimen; selecting an optimal template that is the most similar to a portion of the location measurement transmission image, from the template set by performing pattern matching of each of templates of the template set with the location measurement transmission image; and calculating a specific site location based on the location measurement transmission image and the optimal template. At this time, the transmission image of the specimen has a high probability that it is similar to any template of the thus-generated templates. Therefore, in the specific site location measuring method, the specific site can be measured with higher precision.