A device for controlling an automatic start of an engine mounted on a vehicle provided with a clutch producing two states including a transmitting state where a motive power is transmitted to a driving wheel of the vehicle from an output shaft of the engine by operating a clutch member operated by a driver and a blocking state where the motive power is blocked between the output shaft and the driving wheel by operating the clutch member operated by the driver, and a brake to stop wheels including the driving wheel from rotating by a braking operation of a brake member, the device comprising: an automatic restart processing (52: S10-S40) adapted to restart the engine by driving a starter to perform cranking the engine, the automatic restart processing being performed when predetermined restart conditions are met during automatic stop of the engine; determining means (52: S10-S38) for determining whether or not a transition of the state from the blocking state to the transmitting state occurs while the cranking is being performed, based on a state of the clutch member after the cranking is started by the automatic restart processing during the blocking state; and forced stopping means (52, S40) for forcibly stopping driving of the starter when the determining means determines the transition of the state, wherein the restart condition includes a condition in which the clutch member is operated to allow the state of the clutch to be the transmitting state during the blocking state and a condition in which the braking operation of the brake member is released during the blocking state; and wherein the automatic restart processing performs the cranking by driving the starter and a combustion control process (12, 14, 52) including at least a process for supplying fuel to a combustion chamber of the engine from a fuel injection valve, and the forced stopping means forcibly stops both driving of the starter and the combustion control process when the determining means determines the transition of the state where the blocking state changes to the transmitting state; characterized in that the device includes a setting means for setting a stop prohibited period including a period from a timing at which ignition of the fuel supplied from the fuel injection valve cannot be stopped to a timing at which a compression upper dead point is reached, and the determining means includes a predicting means for predicting whether or not the state of the clutch changes to the transmitting state from the blocking state during the stop prohibited period, and the forced stopping means forcibly stops both driving of the starter and the combustion control process before the stop prohibited period when the predicting means predicts that the state of the clutch will change to the transmitting state from the blocking state. an automatic restart processing (52: S10-S40) adapted to restart the engine by driving a starter to perform cranking the engine, the automatic restart processing being performed when predetermined restart conditions are met during automatic stop of the engine; determining means (52: S10-S38) for determining whether or not a transition of the state from the blocking state to the transmitting state occurs while the cranking is being performed, based on a state of the clutch member after the cranking is started by the automatic restart processing during the blocking state; and forced stopping means (52, S40) for forcibly stopping driving of the starter when the determining means determines the transition of the state, wherein the restart condition includes a condition in which the clutch member is operated to allow the state of the clutch to be the transmitting state during the blocking state and a condition in which the braking operation of the brake member is released during the blocking state; and wherein