To provide an altitude direction flight control device whereby operation is simple with no particular switch required, at emergency time, an altitude can be quickly changed.

An altitude control device 11 is constituted by including a computer 12, CP lever 16, pressure altimeter 18, terrain clearance indicator 19, sensor 23, and a memory 24. In the CP lever 16, a corrective pitch of a rotor is controlled, with a prescribed reference value serving as the center, a spring feel is received. In the sensor 23, a control amount of the CP lever 16 is detected. In the pressure altimeter 18 and the terrain clearance indicator 19, the present altitude of a rotary wing aircraft is measured. The computer 12 compares a difference between the reference value and the control amount with a threshold value, only when the difference is smaller than the threshold value, an altitude of the rotary wing aircraft is feedback-controlled so as to perform flight in a direction conforming the present altitude to a prescribed reference altitude. In this way, by only an input from the CP lever 16, an altitude can be easily changed.