A biological signal processing apparatus includes an obtaining unit that obtains a spectrum of a biological signal that has been obtained, a generation unit that generates a three-dimensional waveform by plotting elements of the spectrum obtained by the obtaining unit in a space defined by a time axis, a frequency axis, and an intensity axis, and a detection unit that detects a specified waveform component using a position along the intensity axis at which a cross-section of the three-dimensional waveform in a time-frequency domain generated by the generation unit is to be observed and a state of the cross-section at the position as criteria for recognition.
