Provided is an automatic blood pressure measurement device, whereby it becomes possible to obtain an accurate pulse wave by properly applying a compression pressure to an artery in a part to be compressed and it also becomes possible to obtain a highly accurate systolic blood pressure value on the basis of the pulse wave.A systolic blood pressure (SBP) value is determined on the basis of a compression pressure to be applied when a first amplitude ratio (R21) (= A2/A1), which is the ratio of an amplitude width value (A2) coming from an intermediate expansion bag (24) to an amplitude width value (A1) of a first pulse wave signal (SM1) coming from an upstream-side expansion bag (22), exceeds a first amplitude ratio change determination value (RR1) and a second amplitude ratio (R32) (= A3/A2), which is the ratio of an amplitude width value (A3) of a third pulse wave signal (SM3) coming from a downstream-side expansion bag (26) to the amplitude width value (A2) of the second pulse wave signal (SM2) coming from the intermediate expansion bag (24), exceeds a second amplitude ratio change determination value (RR2). A highly accurate systolic blood pressure (SBP) value can be obtained on the basis of the first amplitude ratio (R21) and the second amplitude ratio (R32) among the pulse wave signals (SMs).
