An operation device (200) for remotely operating an X-ray imaging device (1) includes an operation unit (280), a grip detection unit (240), which determines whether an operation received by the operation unit (280) is a normal operation or an erroneous operation, and a control unit (230), which transmits an operation signal corresponding to the operation to the X-ray imaging device (1). The control unit (230) transmits the signal when the grip detection unit (240) determines that the operation is a normal operation. The operation device is prevented from causing an erroneous operation of its target device.