To provide a vacuum control valve position detector capable of reducing any production losses caused by defective casting in a vacuum die casting device, easily determining defects of the casting by any defective operation of the vacuum control valve, and allowing an operator to rapidly take actions therefor.

This vacuum control valve position detector has a means for detecting the position of a valve indicating the normal opening/closing operation of the vacuum control valve in a degassing device provided on the vacuum die casting device by a position detector provided continuous to the vacuum control valve, and transmitting the result of detection to a die casting device as the command signal for determining acceptance or rejection of the quality of the casting.