Disable Gravity Acceleration

In my game, I would like to have gravity, but as the GameObject falls, I would like to keep a constant speed. Currently when the object falls it accelerates. How can disable the acceleration of the GameObject when it falls?

You cant use gravity without acceleration. Disable gravity or set it to 0 in your object and in the fixedupdate apply setvelocity(new Vector3(0, -9.8f, 0));