To provide a projection type display using a nonpolar discharge lamp as a light source, capable of widening a variable range for a brightness of a projected image, and capable of maintaining a high contrast ratio even when varying the brightness.

This projection type display 1 has the nonpolar discharge lamp 2 discharge-light-emitted by a high frequency, an LED (auxiliary light source) 3 output-regulated in response to an output from the nonpolar discharge lamp 2, reflectors 4, 5, a reflecting prism (optical member ) 6 for combining lights from the nonpolar discharge lamp 2 and the LED 3, a light integrator (optical member ) 8, a three-plate type light modulation part 11, and a control part (auxiliary light source output control part) 12.