To provide an apparatus and a method for flow injection analysis, with which activity properties of activity control component to an enzyme are assayed.

A transportation medium is sent from a solution feed pump and a sample and the activity control component for controlling reaction activity with an immobilized enzyme held in a column are alternately injected to the transportation medium by an injection device. The peak height A of a sample injected before the activity control component and the peak height B obtained by reaction between a sample injected temporally later than the activity control component and the immobilized enzyme under control detected by a detection device are used to calculate an inhibition ratio or an activation ratio. A recovery ratio is calculated by using the peak height C of a sample injected thereafter so that biochemical characterization between the enzyme and the activity control component is carried out.