A bush-type transmission mount, in which an orifice, operating as a fluid passage that connects a first fluid chamber and a second fluid chamber to each other, is directly formed to a desired length in a core that is coupled to a main rubber to improve vibration-damping characteristics. A membrane is fitted into an outlet portion of the orifice, which communicates with the first fluid chamber, in a sliding manner, thereby improving low-frequency idle vibration and high-frequency dynamic characteristics.