Method for controlling an air purifier by using biorhythm including a first step of calculating total number of days (Delta_Time) a person in a room has lived by using the present year/month/date provided thereto or known through an inner counter, and birth year/month/date of the person in the room provided thereto, a second step of representing a physical rhythm state P_state, an esthetic state E_state, and an intellectual state I_state of the person in the room with the Delta_Time, numerically, a third step of setting a physical weight P-weight, an esthetic weight E, and an intellectual weight in correspondence to the P_state, E_state, and I_state, and a fourth step of controlling operation of the air purifier taking at least one of the P_weight, E_weight, and I_weight into account, whereby operating the purifier according to the biorhythm of the person in the room.