A power transmission control device included in a power transmission device for transmitting power by electromagnetically coupling a primary coil of the power transmission device and a secondary coil of a power receiving device, comprising: a negotiation processing section configured to perform a negotiation process of contactless power transmission, to receive, in the negotiation process, information from the power receiving device, and to confirm, in the negotiation process, whether or not the respective information received from the power receiving device matches respective information of the power transmission device; a setup processing section configured to perform a setup process of the contactless power transmission based on a result of the negotiation process; and a command processing section configured to start normal power transmission from the power transmission device to the power receiving device after the setup process, wherein the setup processing section is configured to: perform the setup process on condition that a match of the respective information received in the negotiation process is confirmed by the negotiation processing section, and to receive, in the setup process, transmission condition information of the contactless power transmission from the power receiving device, so as to set a transmission condition of the contactless power transmission; wherein if in the negotiation process the information received from the power receiving device does not match with the respective information of the power transmission device, setup information exchanged in the setup process is not transferred, and characterized in that: the information received in the negotiation process comprises at least standard information; and the transmission condition information comprises a driving frequency of the primary coil. a negotiation processing section configured to perform a negotiation process of contactless power transmission, to receive, in the negotiation process, information from the power receiving device, and to confirm, in the negotiation process, whether or not the respective information received from the power receiving device matches respective information of the power transmission device; a setup processing section configured to perform a setup process of the contactless power transmission based on a result of the negotiation process; and a command processing section configured to start normal power transmission from the power transmission device to the power receiving device after the setup process, perform the setup process on condition that a match of the respective information received in the negotiation process is confirmed by the negotiation processing section, and to receive, in the setup process, transmission condition information of the contactless power transmission from the power receiving device, so as to set a transmission condition of the contactless power transmission; wherein if in the negotiation process the information received from the power receiving device does not match with the respective information of the power transmission device, setup information exchanged in the setup process is not transferred, and characterized in that: the information received in the negotiation process comprises at least standard information; and the transmission condition information comprises a driving frequency of the primary coil. the information received in the negotiation process comprises at least standard information; and the transmission condition information comprises a driving frequency of the primary coil.