A scanning endoscope system includes an optical fiber configured to guide illumination light, and to emit the illumination light from an end portion, an actuator configured to shift an irradiation position of the illumination light, by swinging the end portion of the optical fiber, a drive signal generator configured to generate and supply a drive signal for driving the actuator, a current measurement section configured to measure, as a current measurement value, a current value of the drive signal supplied to the actuator, and a scan control section configured to perform control such that an amplitude value of the drive signal is switched, and to switch a threshold for detecting the current measurement value from a first threshold to a second threshold, when detecting that the current measurement value gradually changes and reaches the first threshold.
