A data recorder capable of reducing adverse effects caused by radiation is provided. In one aspect of a data recorder of the present disclosure, an input interface includes a first buffer memory, the input interface accepts input of data from outside and records the data in the first buffer memory, a control unit switches a state of a power supply for non-volatile memory to an on state at a timing determined on the basis of an amount of data recorded in the first buffer memory and a mode of the input of the data from the outside via the input interface, the input interface transfers the data recorded in the first buffer memory to the non-volatile memory in a case where the power supply for non-volatile memory is in an on state.