An alpha particle detection apparatus using a dual probe structured ionization chamber and a differential amplifier, the apparatus comprising: an ionization chamber being a cylinder of conductive materials, being open or covered with a wire mesh on a first side thereof, and formed with a plurality of holes on an outer circumferential surface of the cylinder to smoothly circulate air, and electric field configured to be formed thereinside by bias power applied to a surface thereof; a main probe unit disposed within the ionization chamber at a first end thereof,; a guard ring unit coupled to a second side of the ionization chamber so that the main probe unit passes through the ionization chamber, and coupled to a ground to absorb leakage current generated by an occurrence of alpha decay in the ionization chamber and to flow the leakage current to the ground; characterized in the apparatus comprising: an auxiliary probe unit disposed within the ionization chamber by passing through the guard ring unit at a first end thereof, spaced apart from the main probe unit by a predetermined distance, wherein the auxiliary probe unit is arranged within the ionization chamber with an exposure area that is smaller than an exposure area of the main probe unit within the ionization chamber, or wherein the auxiliary probe unit has a length that is shorter than a length of the main probe unit; first and second preamplifiers (500a, 500b) connected to second ends of the main probe unit and the auxiliary probe unit, respectively, and amplifying electrical signals respectively input from the main probe unit and the auxiliary probe unit to a predetermined magnitude; and a differential amplifier connected to output terminals of the first and second preamplifiers (500a, 500b) at a non-inverting terminal (+) and an inverting terminal (-) thereof, respectively, and canceling a noise signal and outputting an alpha particle detection signal by amplifying a voltage difference between the electrical signals preamplified by the first and second preamplifiers (500a, 500b). an ionization chamber being a cylinder of conductive materials, being open or covered with a wire mesh on a first side thereof, and formed with a plurality of holes on an outer circumferential surface of the cylinder to smoothly circulate air, and electric field configured to be formed thereinside by bias power applied to a surface thereof; a main probe unit disposed within the ionization chamber at a first end thereof,; a guard ring unit coupled to a second side of the ionization chamber so that the main probe unit passes through the ionization chamber, and coupled to a ground to absorb leakage current generated by an occurrence of alpha decay in the ionization chamber and to flow the leakage current to the ground; an auxiliary probe unit disposed within the ionization chamber by passing through the guard ring unit at a first end thereof, spaced apart from the main probe unit by a predetermined distance, wherein the auxiliary probe unit is arranged within the ionization chamber with an exposure area that is smaller than an exposure area of the main probe unit within the ionization chamber, or wherein the auxiliary probe unit has a length that is shorter than a length of the main probe unit; first and second preamplifiers (500a, 500b) connected to second ends of the main probe unit and the auxiliary probe unit, respectively, and amplifying electrical signals respectively input from the main probe unit and the auxiliary probe unit to a predetermined magnitude; and a differential amplifier connected to output terminals of the first and second preamplifiers (500a, 500b) at a non-inverting terminal (+) and an inverting terminal (-) thereof, respectively, and canceling a noise signal and outputting an alpha particle detection signal by amplifying a voltage difference between the electrical signals preamplified by the first and second preamplifiers (500a, 500b).