INTERNAL COMBUSTION ENGINE

PROBLEM TO BE SOLVED: To provide an internal combustion engine that can continue operation, even if a malfunction occurs in a compression ratio change mechanism which makes a compression ratio variable, and in which the compression ratio change mechanism is hardly affected by a deposit.SOLUTION: The compression ratio change mechanism 30 which changes the compression ratio by changing a capacity of a variable capacity chamber 35 connected to a combustion chamber 25 is arranged in a position which differs from that of a piston 13 for constituting a movable part of the internal combustion engine 10, an intake valve 15 or an exhaust valve 16. By this arrangement, the compression ratio change mechanism 30 is independent of the operation of the internal combustion engine 10, and does not have an effect on the operation of the internal combustion engine 10. Furthermore, since the compression ratio change mechanism 30 is separated from the piston 13, the intake valve 15 or the exhaust valve 16, the operation of the movable part such as the piston 13, the intake valve 15 or the exhaust valve 16 is not affected by a contamination even if the contamination such as the deposit adheres to a pressure introduction passage 36 of the compression change mechanism 30 and a casing 32.