An apparatus detects fluorescence. In washingdisinfecting the endoscope body, the connector portion is opposed to the endoscope connection portion in the predetermined positioned state, and then, a switch is turned on. The first operation includes applying the first voltage which changes temporally, to some of the electrodes 1, detecting voltages generated on at least some of the remaining electrodes 1 in this state, and detecting the position of the dielectric which is in proximity to the touch panel device, on the basis of the detected voltages.