A centroid position detector device comprising: a load measuring part (50, 52) fitted in contact with the sole side of a foot of a person and configured to measure a value of a load on the sole side of the foot of the person; and a centroid detecting unit configured to detect a position of a center of gravity of the person based on a change in the load value measured by the load measuring part (50, 52); characterised in that: the load measuring part (50, 52) is configured to measure the value of the load on the sole side of the foot of the person based on a capacitance that varies according to a shift of a weight of the person; and the load measuring part (50, 52) comprises: a sheet-like elastic plate having elasticity, an upper electrode bonded to a top surface of the elastic plate, and a lower electrode bonded to a bottom surface of the elastic plate; wherein the load measuring part (50, 52) is arranged to detect a capacitance between the upper electrode and the lower electrode; and wherein one of the upper and lower electrodes is grounded, the other of the upper and lower electrodes is connected to a constant-voltage power source, and the capacitance is computed based on a time taken by a value of a voltage between the upper electrode and the lower electrode to reach a predetermined value. a load measuring part (50, 52) fitted in contact with the sole side of a foot of a person and configured to measure a value of a load on the sole side of the foot of the person; and a centroid detecting unit configured to detect a position of a center of gravity of the person based on a change in the load value measured by the load measuring part (50, 52); characterised in that: the load measuring part (50, 52) is configured to measure the value of the load on the sole side of the foot of the person based on a capacitance that varies according to a shift of a weight of the person; and the load measuring part (50, 52) comprises: a sheet-like elastic plate having elasticity, an upper electrode bonded to a top surface of the elastic plate, and a lower electrode bonded to a bottom surface of the elastic plate; wherein the load measuring part (50, 52) is arranged to detect a capacitance between the upper electrode and the lower electrode; and wherein one of the upper and lower electrodes is grounded, the other of the upper and lower electrodes is connected to a constant-voltage power source, and the capacitance is computed based on a time taken by a value of a voltage between the upper electrode and the lower electrode to reach a predetermined value. the load measuring part (50, 52) is configured to measure the value of the load on the sole side of the foot of the person based on a capacitance that varies according to a shift of a weight of the person; and the load measuring part (50, 52) comprises: a sheet-like elastic plate having elasticity, an upper electrode bonded to a top surface of the elastic plate, and a lower electrode bonded to a bottom surface of the elastic plate; wherein the load measuring part (50, 52) is arranged to detect a capacitance between the upper electrode and the lower electrode; and wherein one of the upper and lower electrodes is grounded, the other of the upper and lower electrodes is connected to a constant-voltage power source, and the capacitance is computed based on a time taken by a value of a voltage between the upper electrode and the lower electrode to reach a predetermined value. a sheet-like elastic plate having elasticity, an upper electrode bonded to a top surface of the elastic plate, and a lower electrode bonded to a bottom surface of the elastic plate; wherein the load measuring part (50, 52) is arranged to detect a capacitance between the upper electrode and the lower electrode; and wherein one of the upper and lower electrodes is grounded, the other of the upper and lower electrodes is connected to a constant-voltage power source, and the capacitance is computed based on a time taken by a value of a voltage between the upper electrode and the lower electrode to reach a predetermined value.