An air conditioner that can present information on a predicted value of stored energy usage per unit time, a predicted value of the electricity charge per unit time, and a predicted value of the amount of CO2 emission per unit time, at the start of operation. The air conditioner includes a predicted electricity efficiency speculating unit that speculates on electricity efficiency, which is stored energy usage per unit time predicted from a set parameter set by the user at the present time, based on a stored value of the recent stored energy usage storing unit, a calculated result of the actual usage electricity efficiency calculating unit, and a compared result of the setting comparing unit, a predicted electricity efficiency calculating unit that calculates an electricity charge per unit time or a predicted amount of CO2 emission efficiency calculating unit that calculates an amount of CO2 emission per unit time, and a displaying unit that displays the calculated information stored energy usage at the start of air conditioner operation.