A stereoscopic image display device (10) includes: a display (12) displaying small images (11) side by side, each of which containing three-dimensional display data, to convert the data into rays and output from the small images (11); first mechanical shutters (14) disposed, corresponding to positions of the small images (11), in front of the display (12), extracting the rays in a time-division manner as partial rays each output from a plurality of partial regions (13) provided in each of the small images (11) and transmitting the partial rays forward; and second mechanical shutters (16) disposed, corresponding to the positions of the small images (11), in front of the first mechanical shutters (14), transmitting forward the partial rays extracted in a time-division manner per each of the small images (11), reconstructing the partial rays as the rays, and converging each of the reconstructed rays in front to form a three-dimensional image.