<p>A processing machine has a main spindle apparatus and a tool holder which clamps a working tool. The main spindle apparatus detachably supports the tool holder and rotates. Oil mist is transported to the working tool through a lubricant supplying pipe in the main spindle apparatus. A coolant hose is formed in the tool holder. A supporting member is composed mainly of a sleeve and a draw bar. The supporting member air-tightly supports the coolant hose of the tool holder. A ring-shaped packing is placed between the lubricant supplying pipe and the supporting member in order to prevent any leakage of the oil mist. The periphery of the packing has two divided sub-parts of a character "Y" shape. The leaking oil mist expands one sub-part of the packing to air-tightly seal the gap formed between the lubricant supplying pipe and the draw bar.</p>
