A scanning endoscope apparatus, comprising a first transmitter, an actuator, a first optical filter, a second optical filter, a second transmitter, a first photo-detection unit, and a position determiner, is provided. The first transmitter transmits light to a first emission end. The actuator moves the first emission end. The first optical filter reflects the light of the first band. The second optical filter transmits the light of the first band at a transmittance that varies according to the position. The second transmitter transmits the light of the first band from a second incident end to a second emission end. The first photo-detection unit detects an amount of the light of the first band. The position determiner determines a position of the first emission end on the basis of the amount of the light of the first band.