A blood pressure measuring apparatus to measure blood pressure based on a change in a pressure by a cuff mounted to a subject comprises: cuff pressure controlling means for deflating the cuff after avascularization by the cuff at a body part around which the cuff is placed; detecting means for detecting the change in a pressure by the cuff and outputting the detection as an electrical signal; extracting means for extracting a pulse wave signal from the electrical signal; and calculating means for calculating a systolic blood pressure value and a diastolic blood pressure value based on a relation between a change rate of an index value which is calculated by multiplying a maximum amplitude of each pulse of the pulse wave signal by the cuff pressure corresponding to the maximum amplitude and a predetermined value. The blood pressure measuring apparatus achieves a high speed measurement while suppressing the reduction of accuracy.