In a lens device provided with a liquid optical element in which the conductive or polar first liquid and the second liquid which is not mixed with the first liquid each other, are sealed and housed in a container so that an interface has a predetermined shape, and when the voltage is impressed between the first liquid and an electrode provided on the container, a shape of the interface is changed and a refractive power is adjusted, because the present invention is characterized in that it has: a plastic lens whose optical characteristic is changed due to the temperature; a temperature detection means for detecting the temperature; and a control means for controlling the voltage to be impressed on the liquid optical element, corresponding the temperature detected by the temperature detection means, so that the influence due to the change of the optical characteristic of the plastic lens and the liquid optical element is decreased, irrespective of the temperature change, the dislocation of the image-formation position to a predetermined image-formation surface can be removed.