A positioning system for an applicator includes a glove for being used for a diagnosis of the affected part, a mark body provided on the glove, an applicator for being inserted into a living body, and an energy emitter provided on the applicator for supplying energy to the living body. The positioning system further includes a sensor provided on the applicator which is capable of detecting the distance to the mark body, a control apparatus for discriminating an optimum position of the applicator based on the distance between the sensor and the mark body while the mark body is disposed in the proximity of the affected part based on a diagnosis performed using the glove, and a display apparatus for displaying a result of the discrimination by the control apparatus.