An electromagnetic flow meter comprises a ceramic measuring pipe formed into a straight cylinder through which fluid to be measured flows, electromagnetic field generating device disposed adjacent to a central portion of an outer surface of the central portion of the ceramic measuring pipe for generating an electromagnetic field into a radial direction of the ceramic measuring pipe, electrodes for detecting an electric potential generated in the fluid, a case which accommodates the ceramic measuring pipe, the electromagnetic field generating device and the electrodes, and sealing members which are disposed between inner surfaces of the flanges of the case and ends of outer circumference of the ceramic measuring pipe. The case has a length longer than that of the ceramic measuring pipe and flanges at both ends thereof. Inner diameters of the flanges are slightly larger than an outer diameter of the ceramic measuring pipe. Portions of the sealing members outwardly project over the end surfaces of the flanges of the case.