IMAGING DEVICE

An imaging device acquires images of a plate-like specimen container having a rectangular shape as seen in top view. The imaging device includes a table, a position reference member, and a holding mechanism. The position reference member includes a first extension and a second extension which intersect at right angles to each other. The holding mechanism includes a rotating plate extending horizontally in plate-like form, and a main body portion for pivoting the rotating plate forwardly in a circumferential direction by means of elastic force of a spring. The rotating plate includes a front wing portion, and a protruding portion protruding forwardly in the circumferential direction from the front wing portion. The specimen container is urged in a second direction to align along the first extension when the rotating plate is pivoted to bring the front wing portion into contact with the specimen container. The specimen container is urged in a first direction to align along the second extension when the protruding portion comes in contact with the specimen container. Thus, the specimen container is aligned and placed in a previously determined position in the imaging device.