In a dual-frequency CW radar apparatus, first/second beat signals that include reflection components of radar waves conforming to transmission signals of first/second frequencies are generated for each antenna element and the generated signals are Fourier transformed. A power spectrum average of the beat signals is used as a basis for the detection of a peak frequency fp corresponding to the frequency of the reflection components. A second eigenvalue λ2 of a correlation matrix: Ry=(½)·[y1,y2][y1,y2]H is calculated, the matrix being based on first received vector y1/second received vector y2 having elements that are Fourier transformed values of the peak frequency fp. Based on the magnitude of the eigenvalue λ2, whether or not the reflection components corresponding to the peak frequency fp are synthetic components of the reflected waves from a plurality of targets is decided.