A hot melt apparatus includes main body, exhaust pin, stopping and resilient members. The main body has hot melt surface, first and second exhaust openings. The first exhaust opening is located on hot melt surface. The main body has channel and chamber. The chamber has abutting surface. The channel is communicated with first exhaust opening and abutting surface. The chamber is communicated with second exhaust opening. The exhaust pin is disposed in channel, and has a pinhead protruding from first exhaust opening and a pintail protruding into chamber. Stopping member is accommodated in chamber and connected to pintail. When the stopping member abuts against the abutting surface, the pinhead open the first exhaust opening. When the pinhead closes the first exhaust opening, the stopping member leaves the abutting surface. The resilient member is accommodated in the chamber for pushing the stopping member toward the abutting surface.