PURPOSE: To solve such a conventional problem that the driving mechanism of a system for turning a heavy camera or a system for turning two sets of prisms in a contrary direction in order to cope with the change of an object distance is complicated.

CONSTITUTION: In a device constituted so that a stereoscopic image is observed by using two images obtained from two photographing systems 1 and 2; deflection members 11 and 12 whose insides are filled with liquid and which can vary the angles of the exit and the entrance of a luminous flux are arranged at the front parts of the systems 1 and 2. Then, the angle varying operation of the defletion members 11 and 12 is executed by interlocking with the operation of the focus parts 1a and 2a of the systems 1 and 2 so that the object focused when the focus parts 1a and 2a are operated and a point where the luminous fluxes of the systems 1 and 2 are deflected by the deflection members 11 and 12 and crossed on the object side are almost aligned.