PROBLEM TO BE SOLVED: To provide an imaging unit that can be manufactured with ease and high accuracy and can be reduced in size, an endoscope device, and a manufacturing method of an imaging unit.SOLUTION: An imaging unit 100 includes: a lens holder 22 that houses an objective lens 20 group in a hollow portion a prism 30 that refracts or transmits light emitted from the objective lens 20 group an imaging element 31 that picks up an image of the light emitted from the prism 30 an imaging holder 32 that houses the prism 30 in a hollow portion and holds the imaging element 31 and a temporary abutting portion 40 that positions the prism 30 at a predetermined position within the imaging holder 32. A part of the lens holder 22 is housed within the imaging holder 32, positions of the lens holder 22 and the imaging holder 32 are temporarily adjusted through the temporary abutting portion 40, and thereafter, by abutting the prism 30 to the lens holder 22 within the imaging holder 32, the prism 30 is positioned at a predetermined position within the imaging holder 32.
