Bio signal amplifying circuit

A bio-signal amplifying circuit is provided to decrease a size and a thickness of the amplifying circuit by realizing the amplifying circuit only using a single operational amplifier and a one-stage high pass filter. A bio-signal amplifying circuit includes an operational amplifier(140), a capacitor load, a feedback capacitor load, and a feedback resistor load. The capacitor load includes a first capacitor(111), which is connected to a first input terminal of the operational amplifier and receives a first voltage from a first electrode, and a second capacitor(112), which is connected to a second input terminal of the operational amplifier and receives a second voltage from a second electrode. The feedback capacitor load includes a first feedback capacitor(121) and a second feedback capacitor(122). The first feedback capacitor is connected to the first input terminal and an output terminal. The second feedback capacitor is connected to the second input terminal. The feedback resistor load includes a first feedback resistor(131), which is connected to the first input terminal and the output terminal, and a second feedback resistor(132), which is connected to the second input terminal.