A blood pressure meter includes an air bladder for attachment to a measurement area, a pressure sensor, a pump a valve, drive circuits, a CPU connected to the pressure sensor and the drive circuits, for controlling the adjustment of the internal pressure of the air bladder and calculating a blood pressure value based on a change in the internal pressure resulting from the adjustment, and a holding portion, into and from which air can flow from and to the air bladder, that has a lower volume than the air bladder. The air can flow from the holding portion into the air bladder in the case where a predetermined pressure is applied to the holding portion. The CPU starts the adjustment of the internal pressure in the case where a change in the internal pressure prior to the start of the adjustment of the internal pressure is a predefined change.