An imaging apparatus for use in an electronic endoscope or the like is provided with a mechanically driven light-shielding plate, wherein imaging is effected by using a solid-state imaging device starting from a time when an amount of light shielded by this light-shielding plate becomes minimal, or imaging is effected repeatedly during a short exposure time within a transient period during which the amount of light shielded becomes minimal, and when an signal level of each image reaches a reference level, that signal is stored in a memory.