A mini pump having a body includes a head, a handheld portion extending from the head and having a groove, a nozzle device having a cover element, a nozzle and an anti-sliding element. The anti-sliding element is disposed on the head and partially received in the groove. The cover element engages the anti-sliding element to the cylinder and prevents the nozzle from coming off the body. The handheld portion and the anti-sliding element are made of resins with different hardnesses. The material of the handheld portion of the body is tougher than that of the anti-sliding element of the nozzle device.