A digital broadcast receiver for determining the actual transmission mode of a Digital Audio Broadcast (DAB) signal with a delay circuit for delaying a received DAB signal is provided. With a correlation circuit for correlating a delay output of the delay circuit with the received DAB signal a moving average circuit for calculating a moving average of a correlation output of the correlation circuit. A transmission mode is assumed to be one of a plurality of transmission modes. The delay time of the delay circuit is set at a time corresponding to a symbol time length of the assumed transmission mode. The number of times that the output of the moving average circuit exceeds a prescribed value is counted. Based on counting results, the actual transmission mode is identified based on the maximum number of times that the output of the moving average circuit exceeds the prescribed value.