To provide an imaging device which can be made low-cost by improving the productivity and eliminating the waste of supply of members and can have its eyepiece replaced with ease.

In a camera 100 as an embodiment of the invention, an eyepiece assembly (d) has a diopter adjusting function and the finder diopter is varied by rotating a cam part (n) by rotating a diopter adjusting member (d) and moving an eyepiece lens (f) along the optical axis by moving a driving pin (m) moving along a cam groove. An eyepiece assembly (e), on the other hand, is an eyepiece with a fixed diopter and an eyepiece lens (f) is fixed. In the final process of assembly, the eyepiece assembly (d) or eyepiece assembly (e) is built in a fitting window c' of a rear cover assembly (c) and those are fitted to an intermediate camera assembly (a) to complete the camera.