There is provided a radar device. A transmission unit includes a transmission antenna for transmitting a signal of a first frequency and a signal of a second frequency. A reception unit includes a first receiving antenna and a second receiving antenna for receiving a first signal obtained by bouncing the signal of the first frequency off a target, and a second signal obtained by bouncing the signal of the second frequency off the target. A control unit determines folding of a first phase difference, based on the first phase difference between the first signal received by the first receiving antenna and the first signal received by the second receiving antenna, a second phase difference between the second signal received by the first receiving antenna and the second signal received by the second receiving antenna, and a difference between the first phase difference and the second phase difference.