An initiator device that supports a single user -multiple input multiple output (MIMO) operation of an IEEE 802.11ay based wireless interface, comprising: a reception circuit; and a control circuit; and a transmission circuit; a generation circuit that generates a first signal including a field indicating which of a reciprocal MIMO phase and a non-reciprocal MIMO phase is applied as a MIMO phase of SU-MIMO beamforming training that is performed before a digital BF procedure of a hybrid BF operation, wherein in a case where both the initiator device and a responder device have antenna pattern reciprocity, a first value is set to the field to indicate that the reciprocal MIMO phase is applied to the SU-MIMO BF training, wherein in a case where the initiator device has the antenna pattern reciprocity, characteristics of transmit antennas and receive antennas of the initiator device match in each direction and a best transmit sector and a best receive sector match, and wherein in a case where the responder device has the antenna pattern reciprocity, characteristics of transmit antennas and receive antennas of the responder device match in each direction and a best transmit sector and a best receive sector match; and the transmission circuit transmits the first signal to the responder device, wherein in a case where the reciprocal MIMO phase is applied to the SU-MIMO BF training, the transmission circuit transmits to the responder device a plurality of first beam refinement protocol signals for training transmit sectors that are to be used for MIMO transmission by the initiator device, the reception circuit receives from the responder device a first MIMO BF feedback signal including feedback information for the first BRP signal, the control circuit determines, on the basis of the feedback information for the first BRP signal, a transmit sector combination and a receive sector combination that are to be used for MIMO transmission by the initiator device, and in contrast to the non-reciprocal MIMO phase, in the reciprocal MIMO phase, reception of a BRP signal corresponding to a SU-MIMO BF training for the responder link and transmission of a MIMO BF feedback signal for BRP signal corresponding to a SU-MIMO BF training for the responder link are omitted. a reception circuit; and a control circuit; and a transmission circuit; a generation circuit that generates a first signal including a field indicating which of a reciprocal MIMO phase and a non-reciprocal MIMO phase is applied as a MIMO phase of SU-MIMO beamforming training that is performed before a digital BF procedure of a hybrid BF operation, wherein in a case where both the initiator device and a responder device have antenna pattern reciprocity, a first value is set to the field to indicate that the reciprocal MIMO phase is applied to the SU-MIMO BF training, wherein in a case where the initiator device has the antenna pattern reciprocity, characteristics of transmit antennas and receive antennas of the initiator device match in each direction and a best transmit sector and a best receive sector match, and wherein in a case where the responder device has the antenna pattern reciprocity, characteristics of transmit antennas and receive antennas of the responder device match in each direction and a best transmit sector and a best receive sector match; and the transmission circuit transmits the first signal to the responder device, wherein in a case where the reciprocal MIMO phase is applied to the SU-MIMO BF training, the transmission circuit transmits to the responder device a plurality of first beam refinement protocol signals for training transmit sectors that are to be used for MIMO transmission by the initiator device, the reception circuit receives from the responder device a first MIMO BF feedback signal including feedback information for the first BRP signal, the control circuit determines, on the basis of the feedback information for the first BRP signal, a transmit sector combination and a receive sector combination that are to be used for MIMO transmission by the initiator device, and in contrast to the non-reciprocal MIMO phase, in the reciprocal MIMO phase, reception of a BRP signal corresponding to a SU-MIMO BF training for the responder link and transmission of a MIMO BF feedback signal for BRP signal corresponding to a SU-MIMO BF training for the responder link are omitted.