Provided are a flowmeter that can measure a flow rate of a liquid with high accuracy and that is easy to carry and handle, and a dialysis machine and a medicinal solution injection device that employ the flowmeter. A flowmeter includes a tube connection member and a measurement instrument body. The tube connection member includes a tube-shaped body, a plurality of resonators that are arranged with gaps there between on an inner wall surface of the body, resonator-side antennas that are connected to the plurality of resonators and a heating element that is arranged between the pluralities of resonators. The measurement instrument body includes measurement-instrument-side antennas, temperature measurement units that are connected to the measurement-instrument-side antennas and measure a temperature, and a flow rate calculation unit that calculates a flow rate on the basis of the temperatures measured by the temperature measurement units.
