A printing apparatus including a separable ink cartridge, a body, and an isolating mechanism is provided. The ink cartridge is formed with a first electronic pad. The body is formed with a circuit board having a second electronic pad. During the installation of the ink cartridge, the isolating mechanism allows the first electronic pad and the second electronic pad to isolate from each other for preventing abrasion. When the ink cartridge reaches to a predetermined position, the function of the isolating mechanism will cease to allow the first electronic pad to contact the second electronic pad.