The present invention relates to a projection type display using a transmission type liquid crystal light valve and its object is to provide a projection type display which does not reduce the reliability due to the change of the working environment. A projection type display of the present invention comprises liquid crystal light valves 4R, 4G and 4B arranged in a body which modulate and emit an incident light form the lamp 2, fans 10 and 12 for cooling the inside of the body, a temperature detecting element 30 for detecting the temperature in the vicinity of the liquid crystal light valve 4G and a control unit 8 for controlling rotational frequencies of the fans 10 and 12 and for controlling on/off of a power source 26 of the lamp 2 based on a compensated temperature after compensating the temperature detected by the temperature detecting element 30 by a predetermined temperature compensation value T0.