An optical member for biological information measurement has a prism, which has a light incident surface being injected with emitted light, a living body tissue measuring section which a living body tissue contacts, and a light emitting surface which emits the light reflected by the living body tissue measuring section which the living body tissue contacts, or the light which has passed the living body tissue through the living body tissue measuring section which the living body tissue has contacted. A prism cover is provided so as to expose the living body tissue measuring section and to surround all or a part of the outer circumferential portion of the prism.