The present invention provides a power voltage supplier for stably supplying a noise-free power voltage without increasing a size of a reservoir capacitor by employing a sharing scheme of the reservoir capacitor. The power voltage supplier of a semiconductor memory device includes: a first power voltage supply line for supplying a first power voltage; a second power voltage supply line for supplying a second power voltage; a first reservoir capacitor for supplying the first and the second power voltages stably; and a reservoir capacitor controller for selectively connecting the first reservoir capacitor to the first power voltage supply line or the second power voltage supply line.