A radar device, comprising: a transmission control unit that generates a reference signal corresponding to a predetermined radar method; a pulse signal generation unit that modulates the reference signal input from the transmission control unit into a pulse signal; a first antenna that radiates the pulse signal from the pulse signal generation unit into air; a second antenna that receives a direct wave from the first antenna and a reflected signal from a target; a frequency conversion unit that uses the reference signal from the transmission control unit so as to convert a frequency of a reception signal received by the second antenna; an A/D conversion unit that creates a digital signal; a storage unit that stores the digital signal from the A/D conversion unit; a frequency analyzing unit that performs frequency analysis on the digital signal stored in the storage unit; a target detection unit that detects, from the signal processed by the frequency analyzing unit, the reflected signal from the target as a target signal; and a target distance and relative speed calculation unit that calculates, from the target signal detected by the target detection unit, a distance and a relative speed of the target, characterized by a wide band filter unit that filters the frequency converted reception signal and has frequency characteristics having a wider band width than a frequency band of the pulse signal, for performing filtering the frequency converted direct wave from the first antenna and the frequency converted reflected signal from the target received by the second antenna so that isolation between transmitting and receiving becomes a desired level or lower, and suppresses unnecessary components in a signal from the frequency conversion unit so as to extract a desired signal; wherein the A/D conversion unit converts an output signal from the wide band filter unit into the digital signal. a transmission control unit that generates a reference signal corresponding to a predetermined radar method; a pulse signal generation unit that modulates the reference signal input from the transmission control unit into a pulse signal; a first antenna that radiates the pulse signal from the pulse signal generation unit into air; a second antenna that receives a direct wave from the first antenna and a reflected signal from a target; a frequency conversion unit that uses the reference signal from the transmission control unit so as to convert a frequency of a reception signal received by the second antenna; an A/D conversion unit that creates a digital signal; a storage unit that stores the digital signal from the A/D conversion unit; a frequency analyzing unit that performs frequency analysis on the digital signal stored in the storage unit; a target detection unit that detects, from the signal processed by the frequency analyzing unit, the reflected signal from the target as a target signal; and a target distance and relative speed calculation unit that calculates, from the target signal detected by the target detection unit, a distance and a relative speed of the target, characterized by a wide band filter unit that filters the frequency converted reception signal and has frequency characteristics having a wider band width than a frequency band of the pulse signal, for performing filtering the frequency converted direct wave from the first antenna and the frequency converted reflected signal from the target received by the second antenna so that isolation between transmitting and receiving becomes a desired level or lower, and suppresses unnecessary components in a signal from the frequency conversion unit so as to extract a desired signal; wherein the A/D conversion unit converts an output signal from the wide band filter unit into the digital signal.