A culture/centrifugal tube includes a tube and a cap. The cap has a disk portion and an annular portion that define an annular groove therebetween. The annular groove opens at a position level with the surface of the disk portion. The open end of the tube extends into the annular groove, with the open end of the vessel in abutment against the surface of the disk portion when the cap is fully engaged on the tube. An angle rotor that is used in a centrifuge is formed with an accommodation hole that receives the culture/centrifugal tube. The accommodation hole including a smaller-diameter tube accommodating portion that accommodates the tube and a larger-diameter cap accommodating portion that accommodates the cap. The cap accommodating portion includes a region that entirely encompasses a corresponding portion of the outer periphery of the annular portion of the cap.