A driver for an electrochromic element is configured to adjust the transmittance of a solution-type electrochromic element to allow the element to display a tone. The element has a pair of electrodes and at least one organic electrochromic material mixed between the electrodes. The driver has an adjusting controller configured to adjust the transmittance of the element. The adjusting controller has controller A and controller B. Controller A is configured to saturate a change in the transmittance of the element to an initial state by applying the voltage which resets the element to the initial state. Controller B is configured to control the tone of the element by applying the voltage which adjusts the transmittance of the element following controller A.