The sprinkler includes the following structural members: a body (1) with a channel for liquid supply, a thermally responsive unit with a valve (4) closing the sprinkler outlet, and a thermally responsive unit attachment. In the first alternative embodiment a sprinkler channel is formed by a segment (10) of a cylindrical configuration connected with a segment (11) made as a conical diffuser. To generate a fine uniform gas-and-drop stream of a high kinetic energy and space-uniform distribution the cylindrical segment (10) length exceeds the channel diameter at this segment. The segment length in the form of conical diffuser exceeds the channel diameter at the cylindrical segment (10). In the second alternative embodiment the sprinkler has two coaxial liquid supply channels. The length of the axial cylindrical channel exceeds its diameter. The second annular channel is coaxial to the first channel and fitted with helical guide components.