An apparatus for extinguishing a lighted cigarette comprises a hollow housing and a cigarette ash storage chamber. A cutter for cutting and extinguishing the burning portion of a lighted cigarette is provided within the housing comprising a bias spring and two pieces of shape memory alloys having different temperature reaction gradients, wherein one of the shape memory alloys is used in the cutter and the other is used in a L-shaped gate. When the burning portion of a cigarette is placed into the inside of the housing and comes into contact with the cutter, the cutter will restore to its memory shape by the temperature response to cut the burning portion of the lighted cigarette and to extinguish the burning portion by pressing it on the gate. Then, the gate will stretch straight to let the cigarette ash drop into the storage container by the temperature response. When the temperature of the gate is decreased, the gate will recover to its original position to cover the storage container, thus, the cigarette ash is restricted within the storage chamber to prevent it from dispersing and cause pollution. If a lighter is attached with the apparatus, it facilitates carrying and provides a safe and clean environment.