An onboard device comprising: a recording section that, at an onboard device installed at a vehicle, is configured to record a control program to be recorded in a first recording medium and configured to carry out processing for controlling the onboard device, and an application program to be recorded in a second recording medium different than the first recording medium and configured to carry out processing on the onboard device; an acquiring section configured to acquire an update package including at least one of a first program configured to update the control program, or a second program configured to update the application program; and an updating section configured to carry out, upon the same occasion, updating of the control program in the first recording medium and the application program in the second recording medium in accordance with the acquired update package in a case in which the acquired update package contains the first program and the second program, wherein the recording section is configured to record, as the control program at the first recording medium, a control program to be currently executed, in a second recording region, and a control program that is one generation before the control program to be currently executed, in a first recording region, and the updating section is configured to update the control program that is one generation before the control program to be executed in a case in which a flag indicates the first recording region and to update the control program to be currently executed in a case in which the flag indicates the second recording region. a recording section that, at an onboard device installed at a vehicle, is configured to record a control program to be recorded in a first recording medium and configured to carry out processing for controlling the onboard device, and an application program to be recorded in a second recording medium different than the first recording medium and configured to carry out processing on the onboard device; an acquiring section configured to acquire an update package including at least one of a first program configured to update the control program, or a second program configured to update the application program; and an updating section configured to carry out, upon the same occasion, updating of the control program in the first recording medium and the application program in the second recording medium in accordance with the acquired update package in a case in which the acquired update package contains the first program and the second program, wherein the recording section is configured to record, as the control program at the first recording medium, a control program to be currently executed, in a second recording region, and a control program that is one generation before the control program to be currently executed, in a first recording region, and the updating section is configured to update the control program that is one generation before the control program to be executed in a case in which a flag indicates the first recording region and to update the control program to be currently executed in a case in which the flag indicates the second recording region.