Power consumption of electric equipment used in a semiconductor manufacturing apparatus (100) is obtained and the total amount is displayed as calories by a display means. The semiconductor manufacturing apparatus is configured so that the equipment is set up inside a housing (10). The amount of heat discharged from the inside to the outside (a clean room) via the housing is obtained, and further, the amount of heat removed by exhaust from the interior of the housing and the amount of heat removed by cooling water that cools the equipment is also obtained, and the total amount of heat is displayed. Additionally, factors pertaining to operating costs such as power consumption are measured and their cost obtained, the amount of power consumed is multiplied by a crude oil conversion coefficient to obtain the amount of CO.sub.2 generated, and the result is displayed. The factors to be measured are measured by a thermocouple, an anemometer and an power meter, and the measurements are input to a personal computer (6) via a conversion module (7).