The Earth Sciences Institute of the Slovak Academy of Sciences (ESI SAS) operates the National Network of Seismic Stations (NNSS) and analyzes instrumental and macroseismic data from earthquakes. The main purpose of the instrumental network is the continuous monitoring of the seismicity of Slovakia and providing high quality data for the seismological scientific research. The first seismographic station of the territory of Slovakia has been installed in 1902. The first digital seismological station of the NNSS has started its operation in 1990. Currently the network consists of eight short period and five broadband stations. The broadband stations are equipped with Streckeisen STS-2, Guralp CMG-6T and Kirnos SKD-30s sensors; the short period stations are equipped with Lennartz LE-3D and Guralp CMG-40T. All stations have real-time data acquisition. The data centre of the NNSS is located at the Earth Sciences Institute in Bratislava. The data are collected by the SeisComp3 software package and a SeedLink server is used for the international data exchange. The NNSS follows an open data policy, seismic waveform data are available in real time without any restriction from the NNSS data centre as well as from the European Integrated Data Archive via the GEOFON data centre. Please, add to the abstract sentence: Slovak seismological pages can be followed at www.seismology.sk .