A fusion splicing apparatus for fusion splicing end portions of optical fiber by butt discharging. Parameter data of a brightness distribution waveform of optical fiber in cross section is measured from a picked up image. A degree of attribution for the measured parameter data is obtained from fuzzy operation data registered in advance, and the type of the optical fiber is identified through a fuzzy operation. The identified type of the optical fiber is collated with fusion splicing conditions for type of optical fibers registered in advance. The collation result is displayed.