A data recording appaxatus for recording control parameters for a control unit in a vehicle, said data recording apparatus comprising: a data recording section for recording the control parameters; a determination section for determining whether or not the control unit terminates an operation for outputting the control parameters to be recorded; a detection section for detecting a signal outputted from the vehicle in association with a turning off of an ignition switch; a control section having switchable shut-down modes including a first shut-down mode and a second shut-down mode, wherein in the first shut-down mode the control section is configured to execute a shut-down processing for shutting down power supply to the data recording apparatus at a timing at which the termination of the operation is determined when the determination section determines that the control unit terminates the operation and wherein in the second shut-down mode the control section is configured to execute the shut-down processing for shutting down power supply to the data recording apparatus at a timing at which the detection is made when the detection section detects the signal outputted in association with the turning off of the ignition switch, wherein the control section is further configured to switch the first shut-down mode and the secondshut-down mode based on an operating condition stored in a mode file, and the operating condition is determined in accordance with acquisition contents or an acquisition condition, said acquisition contents indicative of the type of the control parameters to be recorded, and said acquisition condition indicative of a condition under which the control parameters can be acquired for effectively identifying a faulty condition of the vehicle- and said mode file is previously recorded in the data recording section, wherein the first shut-down mode and the second shut-down mode are switched by the control section. a data recording section for recording the control parameters; a determination section for determining whether or not the control unit terminates an operation for outputting the control parameters to be recorded; a detection section for detecting a signal outputted from the vehicle in association with a turning off of an ignition switch; a control section having switchable shut-down modes including a first shut-down mode and a second shut-down mode, wherein in the first shut-down mode the control section is configured to execute a shut-down processing for shutting down power supply to the data recording apparatus at a timing at which the termination of the operation is determined when the determination section determines that the control unit terminates the operation and wherein in the second shut-down mode the control section is configured to execute the shut-down processing for shutting down power supply to the data recording apparatus at a timing at which the detection is made when the detection section detects the signal outputted in association with the turning off of the ignition switch, wherein the control section is further configured to switch the first shut-down mode and the secondshut-down mode based on an operating condition stored in a mode file, and the operating condition is determined in accordance with acquisition contents or an acquisition condition, said acquisition contents indicative of the type of the control parameters to be recorded, and said acquisition condition indicative of a condition under which the control parameters can be acquired for effectively identifying a faulty condition of the vehicle- and said mode file is previously recorded in the data recording section, wherein the first shut-down mode and the second shut-down mode are switched by the control section.