Bone marrow access apparatus includes a bone penetrating member and a cap. The bone penetrating member includes a tubular insertion portion, and a head portion provided at a proximal end of the tubular insertion portion. A cross-sectional shape of the head portion is wider than a cross-sectional shape of the tubular insertion portion. A recess is provided in the head portion, and an internal channel is provided through the head portion and the tubular insertion portion. The cap accommodates the head portion of the bone penetrating member therein. The cap includes a lower wall which covers at least a part of a distal side of the head portion, and a projection which projects into the recess of the head portion.
