A pulse wave detector which is used while being attached to a wrist (W) of a measurement subject, the pulse wave detector comprising: a body portion which includes a detecting section disposed in a position which is opposed to a radial artery (TD) of the measurement subject and configured to detect a pulse wave from the radial artery (TD); a band which is configured to be wound around the wrist (W) in a state where the band is engaged with the body portion ; a basal-end engaging portion which is disposed on a first end portion of the body portion in a circumferential direction of the wrist (W) and on a side of a surface opposite to a detection surface in the body portion , and with which a basal end portion of the band is engaged; an arbitrary-position engaging portion which is disposed on a second end portion of the body portion in the circumferential direction and on the detection surface , and with which an arbitrary position between the basal end portion engaged with the basal-end engaging portion and a tip end portion of the band is engaged in a folded back state; and engagement members which are configured to detachably engage the tip end portion with the band in a state where the band which is folded back in the arbitrary-position engaging portion and the basal end portion engaged with the basal-end engaging portion overlap with each other, wherein the basal-end engaging portion is configured by a first member which is erected from the first end portion of the body portion and which has a Π-shape, and a first hole portion is formed between the first member and the first end portion of the body portion , wherein the arbitrary-position engaging portion is configured by a second member which is erected from the second end portion of the body portion and which has a Π-shape, and a second hole portion is formed between the second member and the second end portion of the body portion , and wherein the engagement members are formed on surfaces of the basal end portion and the tip end portion of the band . a body portion which includes a detecting section disposed in a position which is opposed to a radial artery (TD) of the measurement subject and configured to detect a pulse wave from the radial artery (TD); a band which is configured to be wound around the wrist (W) in a state where the band is engaged with the body portion ; a basal-end engaging portion which is disposed on a first end portion of the body portion in a circumferential direction of the wrist (W) and on a side of a surface opposite to a detection surface in the body portion , and with which a basal end portion of the band is engaged; an arbitrary-position engaging portion which is disposed on a second end portion of the body portion in the circumferential direction and on the detection surface , and with which an arbitrary position between the basal end portion engaged with the basal-end engaging portion and a tip end portion of the band is engaged in a folded back state; and engagement members which are configured to detachably engage the tip end portion with the band in a state where the band which is folded back in the arbitrary-position engaging portion and the basal end portion engaged with the basal-end engaging portion overlap with each other, wherein the basal-end engaging portion is configured by a first member which is erected from the first end portion of the body portion and which has a Π-shape, and a first hole portion is formed between the first member and the first end portion of the body portion , wherein the arbitrary-position engaging portion is configured by a second member which is erected from the second end portion of the body portion and which has a Π-shape, and a second hole portion is formed between the second member and the second end portion of the body portion , and wherein the engagement members are formed on surfaces of the basal end portion and the tip end portion of the band . <EOS>