PURPOSE: An optical system and a photographing device equipping the same for minimizing the size of the photographing device are provided to make the height of an external appearance compact and minimize the size of the photographing device. CONSTITUTION: An optical system and a photographing device equipping the same for minimizing the size of the photographing device are as follows. An upper side or a lower side of a housing(610) is formed. A first back mirror and a second back mirror are built in the housing. The camera is installed on the first back mirror and the second back mirror. A transverse axis is arranged in the first back mirror and the second back mirror about the field of view to a slope.
