In an endoscope, a solid-state image pickup device images an object, to output an image signal. In a processing apparatus, an illuminator applies normal light and specific light having spectral distribution different from the normal light to the object. A display control unit operates according to the image signal, to cause display of a normal image of the object produced by applying the normal light, and a specific image of the object produced by applying the specific light. A motion detector detects information of relative motion of the object. A controller controls the illuminator, causes alternate emission of the normal and specific light periodically at a storage period of the image pickup device if the motion information is equal to or smaller than a threshold level, and causes emission of the normal light without emitting the specific light if the motion information is greater than the threshold level.
