This projection-type image display device is provided with: a lamp drive unit that drives a lamp; a lamp voltage detection unit that detects a lamp interelectrode voltage (hereinafter referred to as a lamp voltage); an image correction unit that corrects image qualities of image signals to be supplied to an image display element; and a control unit that controls a correction quantity of the image correction unit on the basis of the lamp voltage detected by means of the lamp voltage detection unit. Consequently, deterioration of visibility of a projection image can be suitably suppressed.