The paper describes the background and the present technology of district heating in Finland. District heating started 30 years ago and supplies now close to 200 of the total heat demand for space heating. Number of new district heating plants and consumers are steadily increasing. The present practice of pipeline construction and cost is presented. The uses of transportable heating stations in the growing network are described. Annual cost and tariff structure is described in detail. Typical temperatures in district heating network and connection of consumers are presented, too.