To provide a compact light adjusting device having simple configuration and improved assemblability.

The light adjusting device includes a substrate 101 with an optical aperture formed thereon, a first light adjusting means 301 and a second light adjusting means 401 having optical aperture regulation parts 302 and 402, and a driving source actuating the light adjusting means 301 and 401. The light adjusting means 301 and 401 mutually move to a first rest position retreating from an optical aperture position and a second rest position overlapping the optical aperture position. A rotary shaft member 601 is integrally formed on the first light adjusting means 301, and a coupling part is formed on at least one of the light adjusting means 301 and 401. By rotating the rotary shaft member 601 by the driving source, the light adjusting means 301 is turned, and the light adjusting means 401 is interlocked therewith through the coupling part, whereby the light adjusting means 301 and 401 turn around the same axes of rotation AX1 and AX2.