A light modulation film (1) includes a light modulation layer (30) whose state is reversibly changed between a transparent state by hydrogenation and a reflective state by dehydrogenation, and a catalyst layer (40) that promotes hydrogenation and dehydrogenation in the light modulation layer, in this order on a polymer film substrate (10). light modulation layer (30) includes a light modulation region (32) having a thickness of 10 nm or more on a catalyst layer (40)-side, and an oxidized region (31) on a polymer film substrate (10)-side.