A living body information measurement device of the present invention includes: an insertion/removal opening through which a finger of a living body is to be inserted/removed, a receiving space for receiving the living body finger inserted through the insertion/removal opening, and a mounting main unit having a pad receiving surface facing the receiving space and being configured to receive a pad of the living body finger inserted through the insertion/removal opening, and the mounting main unit has a pair of first finger slippage blocking portions at respective side edges of the pad receiving surface in a perpendicular direction perpendicular to an insertion/removal direction in which the living body finger is to be inserted and removed, the first finger slippage blocking portions extending along the insertion/removal direction and being configured to prevent the living body finger received by the pad receiving surface from being shifted in the perpendicular direction.