Muhammadiyah University of Yogyakarta (UMY) is one of the consumers of electrical energy with considerable use. With this large amount of electricity consumption, awareness of campus residents is needed to behave wisely in the use or utilization of electrical energy. In addition, it is necessary to use more efficient electrical energy equipment. To find out the efficiency of the use of existing electrical equipment, an energy audit is needed. The energy audit was carried out aimed to find out how much electricity consumption and energy load in the F7 building on the 1st to 2nd floor of the Muhammadiyah University of Yogyakarta campus used by FKIK faculty. So that the use of electrical energy in the building becomes more efficient. The F7 building audit was conducted to determine the total energy consumption value (kWh), IKE value, and energy saving opportunities. The results of the study and calculation of the total value of energy used in F7 building is 8243.224 kWh/month with the value of Energy Consumption Intensity ( IKE ) 6.6 kWh/m²/month in the very efficient category. Then because of the air conditioning system (AC) of F7 building needs to be replaced, then the replacement of conventional AC (Non Inverter) to AC Inverter with less power. After saving effort by replacing conventional AC to AC inverter, Total of energy consumption (kWh) in F7 building becomes 6088.59 kWh/month, while the value of Energy Consumption Intensity (IKE) it is 4.6 kWh/m²/month with the category of very efficient. From these calculations, the PHE (Energy Saving Opportunity) value is 2642.64 kWh/month, with a percentage of PHE is 31.37%. From the PHE value, it can also be known that PHB (Cost-Effective Opportunity) of building F7 is up to Rp 2,901,198 per month.