An internal combustion engine having two cylinders 7, 7' having a circular arc shape in the longitudinal direction thereof, one piston 5, 5' being disposed in each of said cylinders so as to be able to move from a position at a minimum distance from the cylinder head P min to a position at a maximum distance from the cylinder head P max, and a shaft 11, the cylinders 7, 7' being disposed such that the motion of the piston 5 in the first cylinder 7 generated by the combustion of fuel in the combustion chamber 4 of the first cylinder 7 and the motion of the piston 5' in the second cylinder 7' generated by the combustion of fuel in the combustion chamber 4' of the second cylinder 7' occur in the same direction, characterized in that one piston rod 6, 6' each, having a circular arc shape in the longitudinal direction thereof, and one freewheel associated with each cylinder 7, 7' are present at the sides of the pistons 5, 5' facing away from the combustion chambers 4, 4', wherein the cylinders 7, 7' are further disposed so that the axis of the shaft 11 is the center point of the circle defining the circular arc shape of the cylinders 7, 7' and of the piston rods 6, 6', the side of each piston rod 6, 6' opposite the piston 5, 5' of the first and the second cylinder 7, 7' is connected to the outer side 8, 8' of one of the freewheels, and the inner sides 10, 10' of the freewheels are each connected to the shaft 11, the freewheels are disposed such that the motion generated by the combustion of fuel in the combustion chamber 4, 4' of a cylinder 7, 7' and transferred by the piston rod 6, 6' of a piston 5, 5' to the outer side of the freewheel 8, 8' is transferred to the shaft 11, and the freewheels each run freely in the opposite direction, and the outer sides of the freewheels 8, 8' are coupled to each other so as to perform a motion in the opposite direction, whereby the motion of the pistons 5, 5' in the first and second cylinder 7, 7' also runs in opposite directions. one piston rod 6, 6' each, having a circular arc shape in the longitudinal direction thereof, and one freewheel associated with each cylinder 7, 7' are present at the sides of the pistons 5, 5' facing away from the combustion chambers 4, 4', wherein the cylinders 7, 7' are further disposed so that the axis of the shaft 11 is the center point of the circle defining the circular arc shape of the cylinders 7, 7' and of the piston rods 6, 6', the side of each piston rod 6, 6' opposite the piston 5, 5' of the first and the second cylinder 7, 7' is connected to the outer side 8, 8' of one of the freewheels, and the inner sides 10, 10' of the freewheels are each connected to the shaft 11, the freewheels are disposed such that the motion generated by the combustion of fuel in the combustion chamber 4, 4' of a cylinder 7, 7' and transferred by the piston rod 6, 6' of a piston 5, 5' to the outer side of the freewheel 8, 8' is transferred to the shaft 11, and the freewheels each run freely in the opposite direction, and the outer sides of the freewheels 8, 8' are coupled to each other so as to perform a motion in the opposite direction, whereby the motion of the pistons 5, 5' in the first and second cylinder 7, 7' also runs in opposite directions.