A respiratory rehabilitation apparatus includes a housing, an adjustment rod provided in the housing to change a pressure load generated during respiration, a pair of stoppers for selectively adjusting respiration pressure, a pair of pressurization-movement parts configured to be pressurized and moved inwards in a longitudinal direction of the housing by respiration pressure during respiration, a pair of elastic members disposed between the pressurization-movement parts and the stoppers, and a pair of diaphragms disposed so as to be in close contact with outer sides in a longitudinal direction of the pressurization-movement parts.