A scanning endoscope, comprising a first transmitter, an actuator, and a mirror, is provided. The first transmitter emits a beam of radiant light from the first emission end. The actuator moves the first emission end in a direction perpendicular to an emission direction. The mirror is arranged from the first emission end to the first direction. The mirror comprises a through-part and a reflection surface. The radiant light emitted from the first emission end passes through the through-part when the first emission end is within a first circumference. The reflection surface reflects the radiant light emitted from the first emission end toward the observation area around the first straight line when the first emission end is outside of the first circumference.