An apparatus which transmits data generated by a device manufacturing apparatus to at least one terminal, comprises a communication unit, a transmission request processor configured to accept or reject a transmission request which the communication unit has received from the terminal, and a transmission controller configured to control the communication unit to transmit, in response to a transmission request accepted by the transmission request processor, data corresponding to the transmission request to a terminal, of the at least one terminal, which has transmitted the transmission request, wherein the transmission request processor accepts a new transmission request if a sum of transmission rates of the respective data concurrently transmitted from the communication unit in response to transmission requests which the transmission request processor has already accepted and a transmission rate at which data is transmitted in response to the new transmission request does not exceed a preset allowable transmission rate.