To provide an internal combustion engine capable of shortening the startup time.

In the internal combustion engine including a second high pressure fuel pump 42 for supplying a fuel Fu to a second delivery pipe 22, a first high pressure fuel pump 41 for supplying the fuel Fu to a first delivery pipe 21, and a shut-off valve 8 for the fuel Fu supplied to the first delivery pipe 21, a bypass pipe 74 is disposed for directly supplying the fuel Fu from a feed pump 5 to the first delivery pipe 21. At startup, modes are switched between a low pressure operation mode in which the shut-off valve 8 is closed and an internal combustion engine body 1 is operated by the fuel Fu directly supplied from the feed pump 5 to the first delivery pipe 21, and a high pressure operation mode in which the shut-off valve 8 is opened and the internal combustion engine body 1 is operated by the fuel Fu supplied from the first high pressure fuel pump 41 and the second high pressure fuel pump 42 to the first delivery pipe 21 and the second delivery pipe 22.