In an air conditioner for a vehicle having first and second air conditioning zones positioned at right and left sides of a front seat in a vehicle compartment and third and fourth air conditioning zones positioned at right and left sides of a rear seat in the vehicle compartment, the air conditioner includes calculating means for calculating each of target blowing-out temperatures of air blown out to the first to fourth air conditioning zones in accordance with environmental conditions and desirable temperatures of the first to fourth air conditioning zones. In the air conditioner, the calculating means corrects an influence from the other air conditioning zones by using a selected desirable temperature in the desirable temperatures of the first to fourth air conditioning zones, while calculating the individual target blowing-out temperatures of the first to fourth air conditioning zones.