[Object] To prevent a user from accidentally pricking the user with a hollow needle when separating blood components using a syringe and a connection device. [Solution] A blood component separation apparatus has three syringes and a connection device 14. The connection device 14 is attached to one syringe and is inserted into other syringes. The connection device 14 has a first member 40 to which a base end of a hollow needle 17 is joined and a second member 60 which is connected to the first member 40 in such a manner as to be able to move relative to the first member 40. The second member 60 is moved back and forth between a first position where a tip 18 of the hollow needle 17 is accommodated and a second position where the tip 18 of the hollow needle 17 is exposed. The second member 60 has elastic portions 63 which are elastically deformed in the movement from the first position to the second position. The elastically deformed elastic portions 63 elastically energize the second member 60 at the second position to the first position side with respect to the first member 40.
