A method for erasing a non-volatile memory is provided. The non-volatile memory includes a first conductive type substrate, a second conductive type well disposed in the first conductive type substrate, a first conductive type well disposed on the second conductive type well, and a memory cell disposed on the first conductive type substrate. The memory cell includes a charge trapping layer and a gate. The erasing method includes the following steps. A first voltage is applied to the gate, a second voltage is applied to the first conductive type substrate, and the second conductive type well is floating. The second voltage is large enough to induce a substrate hot hole effect. The holes are injected into the charge trapping layer by applying the first voltage.