Imaging element, stacked imaging element and solid-state imaging device, and method of manufacturing imaging element

An imaging element includes a photoelectric conversion section 23 including a first electrode 21, a photoelectric conversion layer 23A including an organic material, and a second electrode 22 that are stacked. An inorganic oxide semiconductor material layer 23B including a first layer 23C and a second layer 23D, from side of the first electrode, is formed between the first electrode 21 and the photoelectric conversion layer 23A, and ρ1≥5.9 g/cm3 and ρ1−ρ2≥0.1 g/cm3 are satisfied, where ρ1 is an average film density of the first layer 23C and ρ2 is an average film density of the second layer 23D in a portion extending for 3 nm from an interface between the first electrode 21 and the inorganic oxide semiconductor material layer 23B.