A biological information measurement device may include a body a probe unit and a connection portion which electrically connects the body and the probe unit. The body may include 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 one or more fingers of the subject body. The probe unit may include a light source unit and a light receiving unit and a second fitting portion which is worn on a second fitted portion including a distal phalanx of one or more fingers of the subject body.
