A CPU provides a fluorescent light detecting head with an irradiation instruction, in response to which the fluorescent light detecting head irradiates an ultraviolet ray for detection on an ultraviolet curing resin material to be examined. The CPU then acquires from the fluorescent light detecting head an intensity of a fluorescent light emitted from a photo polymerization initiator included in the ultraviolet curing resin material when receiving the ultraviolet ray for detection. The CPU retrieves a predetermined number of past data of the intensity of the fluorescent light from a storage unit and performs a (moving) average calculation processing to calculate the intensity of the fluorescent light at the current time. The CPU performs an estimation processing of a state of the ultraviolet curing resin material based on the calculated intensity of the fluorescent light.