A memory device and an erase method for the memory device are provided. The memory device includes plural blocks and a controller. The plural blocks include at least one first block and at least one second block. The erase method is controlled by the controller and includes the following steps. A first stage erase operation and a second stage erase operation are sequentially performed on the at least one first block in a first time interval and a second time interval. The first stage erase operation and the second stage erase operation are sequentially performed on the at least one second block in the second time interval and a third time interval.