An agitating device for agitating a blood sample in a sample container is disclosed. The agitating device includes a base comprising a horizontally-supported shaft, a container holder including a first hand and a second hand, the first hand having a first hole at one end and a first hold portion at other end, the second hand having a second hole at one end and a second hold portion at other end, the first and second holes through which the shaft is inserted, the first and second hands being rotatable relative to the shaft and the first and second hold portions faced each other, and an agitation drive unit including a contact member for contacting the container holder and a drive source for reciprocating the contact member contacting the container holder between a lower position and an upper position.