This paper is to present the implementation for maintenance of the 5kW a-Si GPV systems that were installed on the building-top of the Electrical Engineering Department at RMUTSB Nonthaburi, Thailand. The author had studied the way to maintain this system after operating for three years (2004–2006). The maintenance methods are classified into three parts. They are electrical, mechanical and component maintenance. Then the author used the maintenance check list for building-top GPV that author had developed. The period for planned maintenance was on July 2004, July 2005 and July 2006. The results are as follows: 1. The time for GPV shutdown system is 232h or 0.88% of system operating time. 2. The maintenance quantities are 17 times. They are 13 times for electrical maintenance and four times for component maintenance. 3. The time required for maintenance is 50h. Thirty-six hours for electrical maintenance and 14h for component maintenance. 4. The maintenance time (percent) used for the first year was 8%, second year was 20% and the last year was 72%.