A membrane micropump includes a vibration chamber, at least one flow guide, at least one fluid inlet, at least one fluid outlet, at least one inlet rectifier, at least one outlet rectifier, a vibration membrane and an actuator. The vibration chamber includes at least one chamber inlet and at least one chamber outlet. The flow guide can be connected to the chamber inlet, the vibration chamber, the chamber outlet or in the vibration chamber, or it can have more pairs to enhance the effects. The inlet rectifier connects the chamber inlet to the fluid inlet. The outlet rectifier connects the chamber outlet to the fluid outlet. The vibration membrane is disposed on the vibration chamber. The actuator is connected to the vibration membrane to reciprocate the vibration membrane, enabling fluid to flow into the vibration chamber via the fluid inlet and flow out thereof via the fluid outlet.