To shorten a straight terminating part of high pressure piping in a fuel supply device for a large-sized diesel engine equipped with a low pressure region of the fuel supply device and a pump device including at least one high pressure pump for carrying fuel from the low pressure region to a high pressure region of the fuel supply device, wherein high pressure fuel piping extends in the high pressure region between the pump device and a fuel injector added to a cylinder, and at least one curved high pressure fuel piping can be connected to the structural body of the high pressure fuel piping with a connecting member formed at straight terminating ends at both ends thereof through a cylindrical fastening screw having a hollow for passing the high pressure fuel piping, and a male screw at one end.

The hollow (15) of the cylindrical fastening screw (14) of the curved high pressure fuel piping (10) has a spreading part (19) at an end (18) on the opposite side of an end (16) having the male screw (17). Thereby, the straight terminating part of the high pressure piping can be shortened, and a spacial problem can be solved.