PURPOSE: To provide the electronic still camera in which dimmer of a strobe by the TTL dimmer system is put into practical use.

CONSTITUTION: A diaphragm value to a degree of reducing a quantity of a light reflected in a optical fiber arranged in front of an image pickup element and made incident in a dimmer sensor 5 to the extent of not giving an adverse effect onto the accuracy of TTL dimmer is stored in a memory 7 and an open diaphragm limit section 9 controls the diaphragm so that the diaphragm value of the diaphragm 8 is limited to a diaphragm giving a darker diaphragm value than the stored diaphragm value, and then a defect of setting the diaphragm value of the diaphragm 8 to a diaphragm value causing a hindrance to TTL dimmer because of increased quantity of a reflected light in an optical filter made incident in the dimmer sensor 5 is eliminated and the TTL dimmer system is adopted for strobo image pickup for the electronic still camera.