To provide an ink jet recorder in which a very small quantity of ink can be jetted stably even when a colloidal liquid ink produced by dispersing a coloring component uniformly into a high resistance solvent using a surfactant is employed.

A DC bias voltage having a specified magnitude and a jet signal 11 comprising positive and negative continuous pulses of specified width corresponding to an input image signal are generated. The jet signal 11 is superposed on the bias voltage to produce a drive signal 12 having lower voltage than the bias voltage immediately after falling of the jet signal 11. The drive signal 12 is then applied, as an applying jet voltage, to a jet electrode arranged in an ink channel thus jetting ink toward a recording medium.