A test device includes a plurality of transceivers that respectively transmit a wave to a test target point of a test object, respectively receive a wave reflected, scattered, or refracted from the test object, and respectively output a signal generated in response to the received wave; a combiner that combines the plurality of received signals generated by the plurality of transceivers; and a plurality of switches that are opened or closed to transfer the plurality of received signals to the combiner or block the plurality of received signals from being transferred to the combiner.