To provide a stereoscopic display device having a wide visible range angle.

A stereoscopic display device 2 includes: a control means 20; a display means 21; transparent members 23 and 27; a lens array 25 in which a refractive index distribution fiber 25a on which an image for a right eye and an image for a left eye displayed on a display surface 21a are made incident as incident light and whose length is more than 1/2 and less than 1 times the period of the incident light is two-dimensionally arranged so that the erect unmagnified images of the image for a right eye and the image for a left eye are formed in an image forming position away from the light-emitting surface of the refractive index distribution fiber 25a by a predetermined length; and a line type polarizing plate 28 which alternately makes polarization characteristics orthogonal, to alternately output the erect unmagnified images. The thickness of each of the transparent members 23 and 27 is equal to an optical distance from the light-emitting surface of the refractive index distribution fiber 25a to the image forming position.