A pulse wave detecting device in which the attachability can be improved while preventing the position of a pulse wave detection sensor from being displaced is provided. A pulse wave detecting device which is to be used while being attached to the wrist H of a subject includes a housing 20 which accommodates a pulse wave detector 10 for detecting a pulse wave from the radial artery TD. The housing 20 includes: a first housing portion (1a, 1b), and a second housing portion (2) which is lower in rigidity than the first housing portion. The pulse wave detector 10 is accommodated in the first housing portion (1a). A region 2c of the housing 20 is configured by at least the second housing portion (2), the region being contacted with the styloid process Ta of the radius T of the wrist H in a state where the housing 20 is attached to the wrist.
