The muon anomaly $a_\mu=(g-2)/2$ has been measured to 0.54 parts per million by E821 experiment at Brookhaven, and at present there is a 3 to 4-standard deviations difference between the Standard Model prediction and the experimental value.
A new muon $g-2$ experiment, E989, is starting at Fermilab with the aim to improve the experimental error by a factor of four to clarify this difference. Some details of the beam delivery, storage ring and new experimental detector system of the $g-2$ experiment will be presented.