A distance measuring apparatus comprising: a transmission processing section (5, 7) configured to output a transmission signal; an antenna section configured to transmit the transmission signal and receive a reception signal; a reception processing section (4, 8) configured to receive the reception signal or the transmission signal; a filter section configured to perform band limitation on the transmission signal input from one terminal and output the transmission signal from another terminal, and to perform band limitation on the reception signal from the antenna section input from the other terminal and output the reception signal from the one terminal; a distance measuring section configured to perform a distance measurement computation based on the transmission signal transmitted from the transmission processing section (5, 7) and the reception signal received by the reception processing section (4, 8), and to obtain a delay of a signal passing through the filter section and perform calibration of the distance measurement computation; characterized by a signal interruption section configured to interrupt transmission of a signal between the other terminal of the filter section and the antenna section; a control section configured to control the signal interruption section to interrupt the transmission of the signal between the antenna section and the other terminal of the filter section during a period of the calibration; and an interfering wave detection section configured to detect whether or not an interfering wave is received by the antenna section depending on a level of the reception signal received by the reception processing section (4, 8), wherein in a case where it is detected by the interfering wave detection section that the interfering wave is received, the control section does not perform the calibration. a transmission processing section (5, 7) configured to output a transmission signal; an antenna section configured to transmit the transmission signal and receive a reception signal; a reception processing section (4, 8) configured to receive the reception signal or the transmission signal; a filter section configured to perform band limitation on the transmission signal input from one terminal and output the transmission signal from another terminal, and to perform band limitation on the reception signal from the antenna section input from the other terminal and output the reception signal from the one terminal; a distance measuring section configured to perform a distance measurement computation based on the transmission signal transmitted from the transmission processing section (5, 7) and the reception signal received by the reception processing section (4, 8), and to obtain a delay of a signal passing through the filter section and perform calibration of the distance measurement computation; characterized by a signal interruption section configured to interrupt transmission of a signal between the other terminal of the filter section and the antenna section; a control section configured to control the signal interruption section to interrupt the transmission of the signal between the antenna section and the other terminal of the filter section during a period of the calibration; and an interfering wave detection section configured to detect whether or not an interfering wave is received by the antenna section depending on a level of the reception signal received by the reception processing section (4, 8), wherein in a case where it is detected by the interfering wave detection section that the interfering wave is received, the control section does not perform the calibration.