The invention relates to a novel pressure engine, in particular an internal combustion engine which includes an annular structure, a driven shaft running along the annular axis, an annular housing with a housing wall and at least one rotating piston that rotates in the annular housing along a circuit in a sealed manner in relation to the housing. The piston is rotationally fixed to the driven shaft by a connection member and delimits a segment shaped combustion chamber that rotates with the piston, at least on the side lying in the rotation direction when viewed from the combustion chamber. The chamber has connections at given points on the annular housing to a compressed air supply and to an exhaust system. This piston has a piston housing which contains an inner piston which is pushed towards the combustion chamber by a pre-tensioning force.