To provide an atmospheric pressure detection device for engine control, in which the detection frequency and detection accuracy can be improved, in an atmospheric pressure detection.

In step S113, a reference charging efficiency η0n, which is set to be a reference in an operation region which is larger in the change amount of the charging efficiency, as compared to the atmospheric pressure change, is calculated during 1 to 5 min. lapse, after an engine start. When 5 min. has lapsed after the engine start, a charging efficiency ηn in the same operation region as that of the reference charging efficiency η0n is calculated in step S105. In step S106, the change amount Δηn of the charging efficiency is calculated, and the change amount of atmospheric pressure is then calculated, depending on this change amount Δηn in step S107. Thereby, since the change amount of the charging efficiency is calculated in the operation region larger in the change amount, as compared with atmospheric pressure change, the frequency and accuracy of atmospheric pressure detection can be improved.