This paper estimates the outage cost of industries in Thailand. The information of planned outage costs and unplanned outage costs is obtained from surveyed sample of 800 industries in the Provincial Electricity Authority (PEA) service area. The analytical results show that the average unplanned outage costs in Central region, South region, Northeast region, and North region of Thailand are 1,634,117.02 Baht/year, 1,167,333.33 Baht/year, 1,043,197.67 Baht/year and 218,310.81 Baht/year, respectively. In addition, the average planned outage costs are lower than the unplanned outage cost about 60-90%. Moreover, the annual average duration and annual average frequency outage from customer survey are 128.40 minutes/year and 5.46 events/year, respectively. Furthermore, the results in this study indicate that the economic impact of unplanned outage costs is higher than the results of previous study in all PEA service areas although the actual system performances in term of system average outage frequency index (SAIFI) and system average outage duration index (SAIDI) have been continuously improved. Not only economic growth and high technology equipment of industries affect to the increasing of outage cost, but the internal factors of industries such as process characteristic, recovery time, machines and equipment, emergency power supply also involve to the outage costs.