Abstract: An electromagnetic flow meter comprising a circuit for generating signals proportional to the intensity of an A.C. magnetic field impressed on a fluid running through a pipe; a first switch rendered conducting for a prescribed period simultaneously with an A.C. voltage obtained in proportional to the period of the A.C. magnetic field; a second switch actuated after the conduction of the first switch; a circuit for integrating outputs corresponding to the flow rate of a fluid obtained through the first switch and further integrating said outputs with an opposite polarity; a circuit for rendering the second switch nonconducting when an output from said integration circuit reaches a referential level; and a circuit for generating an output corresponding to the period in which said outputs are integrated, for each operating cycle of said integration circuit.