To quickly stop the operation of an internal combustion engine the stop position of which is controlled.

This automatic stop and start device predicts that the requirements for automatic stop are established within a predetermined time when a vehicle speed V is equal to less than a predetermined vehicle speed Vref under the conditions that the other requirements for automatic stop than the requirement for the vehicle stop condition that the vehicle stop V is almost zero (S110 to S130), and prohibits the driving of an air conditioner compressor, and performs stop position control for controlling an engine 22 at a target rotational speed Ne* to stop either of the cylinders of the engine at an angle suitable for the next automatic start (S150, S160). When the vehicle speed V is almost zero, the requirements for automatic stop are established, and the engine rotational speed Ne is stabilized near the target rotational speed Ne* (S180 to S200), the operation of the engine 22 is stopped by stopping the fuel injection of a fuel injection valve 126. Since the fuel injection can be immediately stopped when the requirements for automatic stop are established, the operation of the engine 22 the stop position of which is controlled can be quickly stopped.

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