A projector that outputs a first image and a second image alternately while performing switching between the first image and the second image, includes: a discharge lamp driving section that supplies, to a discharge lamp, a drive current that drives the discharge lamp; a state detecting section that detects a deteriorating state of the discharge lamp; and a control section that controls the discharge lamp driving section, wherein the control section controls the discharge lamp driving section so that the absolute value of the drive current becomes relatively small in a first period and relatively large in a second period and controls the discharge lamp driving section so that the ratio of the absolute value of the drive current in the second period to the absolute value of the drive current in the first period is increased with the progress of the deteriorating state.