A biosignal intensity distribution measuring apparatus, includes a supporting member for supporting a human body, a plurality of detecting portions arranged in two dimensions within a target detection area of the supporting member, the detecting portions detecting pressure fluctuations and outputting signals corresponding to the pressure fluctuations respectively, a filter extracting a biosignal having a predetermined frequency band based from the signal outputted from each of the detecting portions, an intensity calculating portion calculating an intensity value of the biosignal, and an intensity distribution producing portion producing intensity distribution in which the intensity value corresponds to a position of the detecting portion.