An imaging apparatus includes: an imaging processing unit configured to image a subject and output imaging data; a temporary storage medium configured to temporarily store the imaging data output from the imaging processing unit; an imaging control unit configured to control the imaging processing unit; a storage control unit configured to store, in a storage medium detachably mounted to a device main unit, the imaging data temporarily stored in the temporary storage medium; and a request unit configured to request the device main unit for execution of start-up processing; wherein, upon the start-up processing being requested from the request unit, start-up processing of the imaging control unit and the storage control unit are executed in parallel.