A recording device for a railroad vehicle, comprising: detection means for repeatedly detecting, from a vehicle air-conditioning device that performs air conditioning of a passenger compartment of the railroad vehicle, a physical quantity relating to an operation of the vehicle air-conditioning device at a predetermined sampling frequency to generate time-series data indicating detection values of the physical quantity in time series; control means for controlling the vehicle air-conditioning device by outputting control orders to the vehicle air-conditioning device based on the time-series data; abnormality detection means for detecting occurrence of an abnormality in the vehicle air-conditioning device; a tracking memory that is volatile and has a work area to which the time-series data for a predetermined tracking period and control order data for the tracking period are writable, the control order data indicating the control orders; a record holding power accumulator to store power supplied from an overhead wire and to supply the stored power as record holding power to the tracking memory, the record holding power being used by the tracking memory to hold the time-series data for the tracking period and the control order data for the tracking period in the work area; and writing means for (i) sequentially overwriting the time-series data and the control order data to the work area of the tracking memory to sequentially update content recorded in the work area to the time-series data for a latest tracking period and the control order data for the latest tracking period and (ii) stopping overwriting of the time-series data and the control order data to the work area when the abnormality detection means detects occurrence of an abnormality in the vehicle air-conditioning device. detection means for repeatedly detecting, from a vehicle air-conditioning device that performs air conditioning of a passenger compartment of the railroad vehicle, a physical quantity relating to an operation of the vehicle air-conditioning device at a predetermined sampling frequency to generate time-series data indicating detection values of the physical quantity in time series; control means for controlling the vehicle air-conditioning device by outputting control orders to the vehicle air-conditioning device based on the time-series data; abnormality detection means for detecting occurrence of an abnormality in the vehicle air-conditioning device; a tracking memory that is volatile and has a work area to which the time-series data for a predetermined tracking period and control order data for the tracking period are writable, the control order data indicating the control orders; a record holding power accumulator to store power supplied from an overhead wire and to supply the stored power as record holding power to the tracking memory, the record holding power being used by the tracking memory to hold the time-series data for the tracking period and the control order data for the tracking period in the work area; and writing means for (i) sequentially overwriting the time-series data and the control order data to the work area of the tracking memory to sequentially update content recorded in the work area to the time-series data for a latest tracking period and the control order data for the latest tracking period and (ii) stopping overwriting of the time-series data and the control order data to the work area when the abnormality detection means detects occurrence of an abnormality in the vehicle air-conditioning device.