The invention relates to a device (2) for selective catalytic reduction of exhaust gases from internal combustion engines, for uniform distribution of a reducing agent (3) introduced into the exhaust gas stream (1) in the exhaust gas stream (1) at the catalyst inlet, wherein the mixer comprises a structure of mixer elements (21) through which the mixture of exhaust gas (1) and reducing agent (3) is to flow. In order to prevent the deposition of reducing agents on the mixer and to enable an optimal temperature for the subsequent SCR reaction, according to the invention the mixer elements (21) are designed for electrical heating having an electric current flowing through them because of the electrical resistance thereof. A very high degree of efficiency in relation to the power used can be achieved by the direct heating. The heat is emitted at the locations at which the heat is needed. The structure as a whole can be configured in a very cost-effective manner. The invention further relates to a device for selective catalytic reaction of exhaust gas from an internal combustion engine having an exhaust gas pipe leading to a mixer according to the invention and having a reducing agent pipe which is connected to a reservoir for reducing agent and which opens into the exhaust gas pipe in the flow direction before the mixer (5), and a catalyst (7) downstream of the mixer (5) in the flow direction.