An apparatus for inspecting a function of an endothelium of a blood vessel of a living being, by stopping, using an inflatable cuff wound around a forearm of the living being, a flow of blood in a blood vessel of the forearm, subsequently ending the stopping of the flow of blood, and causing an ultrasonic probe placed on a skin of an upper arm of the living being to emit, from an emission surface thereof, an ultrasonic wave toward a blood vessel under the skin, the apparatus including an elbow-portion support member which supports an elbow portion of the living being; and a hand-dorsal-portion support member which supports a dorsal portion of a hand of the living being and which cooperates with the elbow-portion support member to keep, in a space, the inflatable cuff wound around the forearm of the living being.