A biosignal measurement apparatus is used by being affixed on a living body. The apparatus includes an affixed part that is a sheet, in which a signal-acquiring section of multiple electrodes and wiring connected to each of the electrodes are formed, and which can be freely expanded, contracted and bent and is adhesive; and a substrate that is connected to the wiring and on which a signal-processing circuit for wirelessly transmitting biosignals obtained through the wiring is mounted. The signal-acquiring section is exposed on the surface of the affixed part and the affixed part and the substrate are stacked so that the back surface of the affixed part faces the substrate.