A puncture set includes a puncture needle unit and puncture device. The puncture needle unit includes a puncture needle and a tubular casing, with the puncture needle having a needle hub and a needle body possessing a needle point. The tubular casing movably receives the puncture needle and has an opening from which the needle point can project. The puncture device has a housing, an installation section at which the casing is removably installed, and a plunger having a connection section connected to the needle hub in an installed state where the casing is installed on the installation section. Casing-side projections project from the outer periphery of the casing and are circumferentially arranged. Installation section-side projections project from the inner periphery of the installation section and are circumferentially arranged. In the installed state, at least one installation section-side projection is located between adjacent casing-side projections.
