To provide an action of an upright piano which permits playing of repeated notes on the single key and touch of the keys that are comparable to a grand piano. A first spring (59) is provided to a pushing-up portion (20) of a jack (18), a first spring rest (71) is provided to a jack stop rail (53), and when a jack tail (19) moves away from a regulating button (47), the first spring (59) bent between the pushing-up portion (20) and the first spring rest (71) forces the pushing-up portion (20) to be pushed under a pushed-up portion (27) to be thrust up of a hammer butt (25). A second spring (66) is provided to a damper stop rail (56), a second spring rest (72) is provided to a hammer shank (33), and the second spring (66) bent between the damper stop rail (56) and the second spring rest (72) stops the rotational movement of a hammer (32) before the hammer (32) that moves rotationally by the force of the first spring (59) strikes a string (90).