In order to provide a biological information measurement device which ensures sturdiness, less easily falls off a finger and less easily inhibits a blood flow by measurement performed over an extended period of time, there is provided a biological information measurement device which acquires biological information of a subject body by receiving, in a light receiving unit, light emitted from a light source unit while a finger of the subject body is inserted into space between the light source unit and the light receiving unit, the device including a body, a probe unit, and a connection portion electrically connecting the body and the probe unit. Here, the body includes a casing in which a battery and an electrical circuit are incorporated, and a first fitting portion which is attached to the casing and worn on a first fitted portion including a portion of at least one of a proximal phalanx and a middle phalanx of the finger. Moreover, the probe unit includes the light source unit and the light receiving unit, as well as a second fitting portion that is worn on a second fitted portion including a distal phalanx of the finger.
