To provide a common rail excellent in durability and airtightness for preventing leakage of pressurized fuel supplied in a rail hole while increasing internal pressure fatigue strength around an opening of a branch hole in an inner wall of the rail hole, and to provide a manufacturing method of the common rail.

The common rail comprises: a rail main body part 10 having the rail hole 11 extending in a longitudinal direction and the branch hole 12 extending in a direction orthogonal to the rail hole; a branch part 20 providing a communicating passage 21 connecting the branch hole 12 with fuel piping 41; and a cast-metal part 30 cast around the rail main body part 10 to insert the rail main body part. Even when internal pressure in the rail hole 11 is increased caused by supply of high pressure fuel, since the cast-metal part 31 resists to the expansion of the rail main body part 10 and relative compressive force as its reaction is applied to the rail main body part 10, the internal pressure fatigue strength around the opening of the branch hole 12 opening on a fail hole 11 side is increased.