An optical scanning endoscope device includes: a laser element； an optical fiber that guides laser light from the laser element； a first detector that detects a guided light amount of the laser light in the optical fiber； a second detector that detects light from a subject and outputs a detection signal； a first calculator that calculates an optical coupling ratio between the laser element and the optical fiber on the basis of the guided light amount； a second calculator that calculates a degradation ratio of the laser element on the basis of the guided light amount； a first adjuster that adjusts the magnitude of the detection signal on the basis of the optical coupling ratio； and a second adjuster that adjusts the output light amount of the laser light from the laser element on the basis of the degradation ratio.
