An ink jet printer is provided with a piezoelectric element which is provided corresponding to a pressure chamber in order to discharge liquid droplets, a driving signal generating section which generates a driving signal, a residual vibration detecting section which detects changes in an electromotive force of the piezoelectric element in accordance with the residual vibration inside the pressure chamber which occur after the driving signal is applied, a first switch which switches whether or not a driving signal is applied to the piezoelectric element, and a second switch which switches whether or not a change in the electromotive force is supplied to a first high-pass filter, where the second switch and the residual vibration detecting section are connected via a first capacitor of the first high-pass filter.