A modulation scheme estimation apparatus includes a receiving unit receiving a first signal, a generation unit generating a plurality of first phase amounts, an acquisition unit acquiring a plurality of multiplication signals by multiplying the first signal by each of the first phase amounts, an extraction unit extracting a plurality of second signals corresponding to respective direct-current components of third signals obtained by subjecting the multiplication signals to Fourier transform, a first computation unit computing a plurality of sums, each of which is a sum of each of the multiplication signals and a corresponding one of the second signals, a second computation unit computing a plurality of absolute values of the sums, and a first identifying unit identifying a modulation scheme corresponding to one of the absolute values which has a highest similarity with respect to reference values associated with modulation schemes.