Abstract: A fuel supply apparatus for use with a gaseous fuel engine is provided with an intake passage having an inlet port open to a cylinder and adapted for supplying air into the cylinder therethrough; a fuel supply device for supplying gaseous fuel into the cylinder, the fuel supply device including at least two fuel supply systems each of which is provided with fuel amount adjusting mechanism for adjusting an amount of gaseous fuel to be supplied, the fuel supply systems including high and low pressure fuel supply systems used in a high induction zone where a large amount of air is admitted into the cylinder and in a low induction zone where a small amount of air is admitted into the cylinder, the high pressure fuel supply system being constructed so that the gaseous fuel is supplied into the cylinder during a former half of a compression stroke following an air intake stroke of the engine at a pressure higher than a pressure in the cylinder through a gaseous fuel supply port open to the cylinder independently of