A scanning endoscope, comprising a first transmitter, an actuator, and a mirror, is provided. The first transmitter emits a beam of radiant light from an emission end. The actuator moves the emission end in a direction perpendicular to an emission direction. The mirror is arranged from the emission end in the emission direction when the emission end is on a predetermined standard point. The mirror comprises a reflection surface around a first straight line. The distance between a first position on the first straight line to any second position on the reflection surface increases as the first position is moved in the first direction. The reflection surface reflects the radiant light emitted from the first transmitter toward the observation area around the first straight line.