There is provided an idling stop device. An ECU sets a lighting color index by recognizing a lighting color of a traffic light in front of a vehicle based upon external environment captured by an onboard camera, sets a distance index based upon a distance between the traffic light and a vehicle just in front of the vehicle, and sets a brake index based upon whether a brake lamp of the vehicle just in front of the vehicle is turned on or not. The ECU adds up these indices to obtain an ISS general index, sets a basic ISS speed based upon the ISS general index, and sets an ISS start speed based upon the basic ISS speed and a mode-based coefficient set based upon an engine mode.