To provide a comfortable environment close to an environment right before a power failure to a user in an elevator car even at the occurrence of the power failure by reflecting a ventilation state before the power failure to an operation state of a ventilation device after the power failure in a ventilation control system in the elevator car.

The ventilation control system in the elevator car includes the ventilation device 18 arranged in the car 16 and operated by electric power from an AC power supply device 12, a change-over switch 20 arranged between a battery 14 and the ventilation device 18 and allowing supply of the electric power from the battery 14 to the ventilation device 18 by connection, a voltage monitoring device 24 detecting a voltage abnormality of the AC power supply device 12, a normal operation state obtaining means for obtaining the newest operation state of the ventilation device 18 before the detection of the voltage abnormality from a storage means when the voltage abnormality of the AC power supply device 12 is detected, and a connection control means for controlling the connection state of the change-over switch 20 in accordance with the newest operation state of the ventilation device 18 after the detection of the voltage abnormality of the AC power supply device 12.