A device for measuring a flow rate of Ringer's solution includes a key input unit including a number input key through which a user can make an input each time when a drip drips in a drip chamber; a power supply unit for supplying power; an oscillation circuit for oscillating a signal having a preset frequency; a display unit for quantitatively outputting a calculated flow rate of Ringer's solution; and a control unit for calculating an elapsed time when the input is made through the number input key of the key input unit for a preset number of times, calculating the number of drips per an hour using the preset number of times and the calculated elapsed time, acquiring a quantitative flow rate of Ringer's solution by multiplying a preset volume of each drip and the calculated number of drips, and outputting the acquired flow rate to the display unit.