The invention relates to an oscillating piston machine, the casing (12) of which has a spherical inner wall, and four pistons (32-38) are arranged in the casing, and they jointly rotate around a rotation axis (40), and each of the four pistons Two pistons diametrically opposed to the center of the housing form a rigid pair of pistons (32/36, 34/38) which can pivot about a common axis of oscillation perpendicular to the axis of rotation (40) ( 42) Swing back and forth in reverse, the two piston pairs are arranged through the cross joint relative to the swing axis, so that the two pistons of the two piston pairs face each other with their working surfaces, so as to form a working surface between the working surfaces. Cavities (48, 50), each pair of pistons has a supporting section (52, 56) for supporting the pair of pistons on the swing axis, and each of the two pistons of the pair of pistons has a side wall section (54) for forming them respectively A lateral boundary of a working chamber. The support section and the side wall section are designed in one piece and are arranged on the same side of the respective piston pair.