Electrical energy has now become primary energy because electricity is always needed in all activities, both in the industrial sector and in everyday life. This requires PT PLN (Persero) as a service provider and sales of electricity to deliver quality electricity. In this paper, data processing and analysis were carried out on the reliability of WBN-01 feeders from Wirobrajan Substation, Rayon Kota Yogyakarta during the 2017 period, with section technique method. This method works by dividing the section only on one feeder, so the results obtained are more detail. WBN-01 feeder is divided into 5 sections, in which there are 136 load points and 111 Kms network length. The parameters used were SPLN 68-2: 1986. The results of the analysis of this study, WBN-01 feeders during 2017 had a value of SAIFI 2,72870496 times / year and SAIDI 3,45250576 hours / year. If we compare this result to the parameter, we can say that the WBN-01 feeder is in good condition and reliable, because the nominal is lower than maximum point. Next is the calculation of ENS (Energy Not Supplied) and AENS (Average Energy Not Supplied) with the results of ΣENS 82350,768 kWh and AENS 10.47586414 kWh / customer. It is expected that by carrying out this research, the causes of frequent disturbances can be reduced and the quality of the distribution of electrical energy in WBN-01 feeders becomes better substation.