A vehicle log transmission device includes: a vehicle log division processor that generates one or more divided logs; existing identifier storage that stores an existing identifier list, which is a list of identifiers corresponding to existing divided logs generated by dividing an existing vehicle log shared between the vehicle log transmission device and a vehicle log analysis server; a vehicle log transmission necessity determiner that determines that a divided log corresponding to an identifier present in the existing identifier list is a first divided log, and that a divided log corresponding to an identifier not present in the existing identifier list is a second divided log; and a vehicle-side communicator that transmits the identifier corresponding to the first divided log to the vehicle log analysis server, and transmits the second divided log to the vehicle log analysis server.