An object is to acquire an image that is focused at an appropriate position, while enabling switching of the observation direction between direct view and oblique view. Provided is an image-acquisition device (1) including an objective optical system (2) that forms an optical image of an object an image-acquisition element (3) that acquires an image of the optical image formed by the objective optical system (2) an optical component (4) that can be inserted into and removed from the optical axis of the objective optical system (2), at an intermediate position on the optical axis and a moving mechanism that moves the optical component (4) between a position on the optical axis of the objective optical system (2) and a position off the optical axis. The optical component (4) has a deflecting surface (4a) for deflecting the optical axis of the objective optical system (2) and a refracting surface (4b) having power.
