The invention relates to a blade for a turbine comprising a blade wall, a first channel for guiding a first medium and a second channel for guiding a second medium that can be supplied to the turbine blade separately from the first medium. In order to combine both media, which are supplied separately, into one mixture, a turbine blade has least one chamber which is arranged in the interior or in the blade wall and said chamber is connected to said channels via a respective connection line. In order to provide a particularly simple component that is economical to produce, the chamber and/or the outlet conduit are a least partially delimited and/or formed by an insert accommodated in the wall.