Provided is a liquid droplet forming device including: a liquid container capable of containing a liquid; a membranous member disposed at a bottom of the liquid container and including a discharging hole; a deforming unit capable of deforming the membranous member; and a driving unit configured to drive the deforming unit by outputting a discharging signal for deforming the membranous member to discharge the liquid or a suppressing signal for suppressing residual vibration of the membranous member, wherein the suppressing signal is a signal based on natural vibration period T0 of the membranous member, wherein an amplitude of the suppressing signal is lower than or equal to an amplitude of the discharging signal, and wherein interval time Ti from when outputting of the discharging signal is ended until when outputting of the suppressing signal is started satisfies a formula: Ti=(m−½)×T0, where m represents a positive integer.