A blood pressure monitor includes a main unit casing placed on a table, a living body insert portion casing of an approximately cylindrical shape, positioned on the main unit casing in a non-use state and having a cuff arranged on its inner peripheral surface, the cuff having a hollow portion to which an upper arm of a subject is inserted, and a connection mechanism for connecting the living body insert portion casing with the main unit casing in a movable manner such that, upon application of the cuff to the subject, the living body insert portion casing can move to come closer to the subject than the main unit casing. Thus, a blood pressure monitor provided with an automatic cuff winding mechanism enabling measurement of blood pressure with high accuracy, not giving unnecessary pain to the subject, and allowing measurement with an unconstrained posture can be provided.