A pulse wave detecting device includes a sensor section and a control unit. The sensor section is rotatable about a first axis and is rotatable about a second axis. The control unit determines a rotation angle about the second axis and a rotation angle about the first axis in a state where a roll angle of the sensor section is controlled to the optimal roll angle. Then, the control unit, presses the sensor section against the body surface in a state where the sensor section is controlled into the optimal roll angle and the optimal pitch angle, detects a pulse wave based on pressure signals detected by pressure detecting elements during the increase, and calculates vital information based on the detected pulse wave.