A train information managing apparatus according to the present invention includes: a terminal apparatus that communicates with a train-mounted device; and a central apparatus that communicates with the terminal apparatus and the train-mounted device. In at least one of the terminal apparatus and the central apparatus, a processing system that includes a signal processing unit is duplicated, the signal processing unit generating a command signal for the train-mounted device and receiving a response signal made in response to the command signal, and at least one of the signal processing units that receive a response signal from the train-mounted device transmits, to another of the signal processing units, information indicating receipt of the response signal so as to be used to determine a failure in one of the processing systems.