A projection display apparatus includes an image projecting unit projecting an image, an operation unit as an operation device whose output value changes depending on the amount of operation, a correction amount setting unit changing a keystone correction amount in accordance with an output value of the operation unit, and a keystone correcting unit performing keystone correction on an image to be projected in accordance with the keystone correction amount. A zero reference position in which the keystone correction amount is zero is set in an operation range of the operation unit. The correction amount setting unit sets a dead zone in the operation range such that the dead zone includes the zero reference position and an area surrounding this position, and sets the keystone correction amount to zero in accordance with the output value corresponding to the inside of the dead zone.