An exciting circuit for an electromagnetic flow meter of a switching control system comprising: four switching elements (Q1, Q2, Q3, Q4) having first and second ends, wherein a first and third switching element (Q1, Q3) is connected with their first ends at a first point and a second and fourth switching element (Q2, Q4) is connected with their first ends at a second point, wherein the switching of the switching elements (Q1, Q2, Q3, Q4) are controlled by timing signals (T1, T2, T3, T4), an exciting coil (COIL) arranged between the first and second points (13, 15), a DC power source for applying an exciting current to the exciting coil (COIL) via the switching elements (Q1, Q2, Q3, Q4), wherein one end of the DC power source is connected to the second end of the first switching element and to the second end of the second switching element, wherein the other end of the DC power source is connected to the third switching element and to the fourth switching element, wherein a direction of the exciting current, flowing through the exciting coil (COIL), is switched over by the switching elements (Q1, Q2, Q3, Q4) at a predetermined fundamental excitation frequency, and wherein the switching elements are controlled so as to hold the exciting current to be a predetermined value, characterized by a first detection resistor connected with one of its ends to the second end of the third switching element, a second detection resistor connected with one of its ends to the second end of the fourth switching element, and the first and second detection resitors (R25, R26) are connected to each other with its other ends at a midpoint, wherein the midpoint is grounded, thereby generating between the one end of the first detection resistor and the midpoint a first reference voltage (VREF1) and between the one end of the second detection resistor and the midpoint a second reference voltage (VREF2). four switching elements (Q1, Q2, Q3, Q4) having first and second ends, wherein a first and third switching element (Q1, Q3) is connected with their first ends at a first point and a second and fourth switching element (Q2, Q4) is connected with their first ends at a second point, wherein the switching of the switching elements (Q1, Q2, Q3, Q4) are controlled by timing signals (T1, T2, T3, T4), an exciting coil (COIL) arranged between the first and second points (13, 15), a DC power source for applying an exciting current to the exciting coil (COIL) via the switching elements (Q1, Q2, Q3, Q4), wherein one end of the DC power source is connected to the second end of the first switching element and to the second end of the second switching element, wherein the other end of the DC power source is connected to the third switching element and to the fourth switching element, wherein a direction of the exciting current, flowing through the exciting coil (COIL), is switched over by the switching elements (Q1, Q2, Q3, Q4) at a predetermined fundamental excitation frequency, and wherein the switching elements are controlled so as to hold the exciting current to be a predetermined value, characterized by a first detection resistor connected with one of its ends to the second end of the third switching element, a second detection resistor connected with one of its ends to the second end of the fourth switching element, and the first and second detection resitors (R25, R26) are connected to each other with its other ends at a midpoint, wherein the midpoint is grounded, thereby generating between the one end of the first detection resistor and the midpoint a first reference voltage (VREF1) and between the one end of the second detection resistor and the midpoint a second reference voltage (VREF2).