According to one embodiment, a sensor attachment/detachment device of the embodiment includes a sensor, a bonding member, a support portion, and a release execution portion. The bonding member is bonded to a first surface of the sensor and has a function of decreasing an adhesive force. The support portion can support the sensor by directly contacting a second surface of the sensor or via another functional portion. The release execution portion performs a process of releasing the bonding member from the object by decreasing the adhesive force of the bonding member after the sensor is attached to the object by the bonding member.