An engine device includes a pressure regulator coupled to the engine, a container, and a needle tube mechanism disposed in the container and having a block coupled to the engine with a pipe, to receive gas from the engine. The block includes a slit connected to the pipe and a channel communicating with the slit and the chamber of the container, the slit of the block includes an inner diameter smaller than that of the channel of the block, and arranged to allow the gas from the engine to flow through the slit and the channel of the block when the engine is over-pressurized, and to allow the gas in the container to flow into the engine in order to balance a pressure in the engine when the pressure in the engine is too low.