Electromagnetic flowmeter

The invention provides an electromagnetic flowmeter which is provided with a built-in temperature sensor in order to avoid the influence of heat radiation and heat of a heat-generating component and can measure the temperature of a fluid with high precision. This electromagnetic flow meter is provided with a measurement tube (14), excitation coils (15, 16), an upstream joint (21), a downstream joint (22), and a first sub-substrate (17) disposed between the upstream joint (21) and the excitation coils (15, 16). The electromagnetic flowmeter is provided with a housing (12) that accommodates a measurement tube (14), excitation coils (15, 16), and a first sub-substrate (17). The electromagnetic flowmeter is provided with a main substrate (19) that is attached to the opening (12a) of the housing (12) and that forms a second space (S1b) (closed space) in the interior of the housing (12), the second space (S1b) having the upstream-side joint (21) and the first sub-substrate (17) as a partial wall. A temperature sens