A heart beat/respiration measuring device comprising a sheet-like capacitance-type pressure sensor adapted to be pressed against the human body, and a measuring circuit for measuring a heart rate and/or respiration rate from the output of the sensor. The capacitance-type pressure sensor includes a sheet-like dielectric body elastically deformable in all directions and a pair of conductive clothes with stretchability disposed on opposite sides of the dielectric body. The measuring circuit comprises a resonant circuit wherein the capacitance-type pressure sensor serves as an oscillation capacitor, and a calculation processing circuit for detecting variations in the oscillation frequency of the resonant circuit and calculating the heart rate and/or respiration rate based on the frequency component or components of heart beats and/or respiration included in the variations.