INTERNAL COMBUSTION ENGINE

There is provided an internal combustion engine (E) including: a crankshaft (31); a first cylinder (7) and a second cylinder (8); and a decompression device (9) configured to reduce the pressures inside the first cylinder and the second cylinder at a time when the internal combustion engine starts to rotationally drive as compared with the pressures inside the first cylinder and the second cylinder at a time after the internal combustion engine starts to rotationally drive. The decompression device is configured such that, at the time when the internal combustion engine starts to rotationally drive, a decompression amount in the second cylinder is greater than a decompression amount in the first cylinder.