The present combustor of gas turbine engine includes: a fuel injection unit including a fuel spray part to spray a fuel so that a diffusion combustion region is formed in a combustion chamber, and a pre-mixture supply part to supply a pre-mixture of a fuel and an air so that a pre-mixture combustion region is formed in the combustion chamber; and a fuel supply unit to supply the fuel to the fuel spray part and pre-mixture supply part. The fuel supply unit includes: a pilot fuel passage and a main fuel passage to supply the fuel to the fuel spray part and the pre-mixture supply part, respectively; an assembled fuel passage to supply the fuel to the pilot and main fuel passages; and a fuel distributor disposed at a branch point where the assembled fuel passage is connected to both the pilot and main fuel passages. The fuel distributor is configured to automatically control amounts of the fuel to be distributed to the pilot fuel passage and to the main fuel passage in accordance with the fuel pressure.