An analysis device includes a separation chamber, a holding channel, a mixing chamber connected to the holding channel, an overflow channel connected between the holding channel and the separation chamber, a sample overflow chamber into which a sample solution remaining in the separation chamber is discharged, and a joint channel connecting the separation chamber and the sample overflow chamber. After the separated solution component fills the overflow channel with priority, a separated solid component is transferred to the holding channel via the overflow channel, and a predetermined amount of the solid component is measured. The solid component in the holding channel is transferred to the mixing chamber by a centrifugal force, and simultaneously, the sample solution remaining in the separation chamber is discharged to the sample overflow chamber by the siphon effect of the joint channel.