To measure internal information on the subject, the OCT (optical coherence tomographic) control device is equipped with: a first imaging control means for initiating imaging when it is determined that input of a measurement instruction to scan the laser light at a prescribed pitch in the imaging target area of a sample using the galvano mirror has been received, and completing imaging in an imaging time that matches the prescribed pitch; and with a second imaging control means for initiating imaging when it is determined that input of a preview instruction to scan at a coarser pitch than the prescribed pitch has been received, and for completing imaging when it is determined that input of a measurement instruction as an instruction to cancel the preview instruction has been received.