A gait measurement device includes a first sensor that outputs an activation signal in response to detection of a magnetic field, a clock that generates a clock count value, a second sensor that measures a physical quantity related to movement of a foot, a control unit that is activated in response to the activation signal output from the first sensor to activate the clock and the second sensor, a data generation unit that generates sensor data using the physical quantity measured by the second sensor and generates measurement data associated with the clock count value and the sensor data at a timing when the physical quantity is measured, and an output unit that outputs the measurement data.